Sure, that’s fair. So a big one for me is something that has already been mentioned in this topic:
Essentially, the short (perhaps even text-less), but nonetheless compelling, emotional, and deserving-of-interaction type of content. Yes, that could happen in Discourse today, but there are several barriers to it happening naturally. Having an entire topic for it seems a bit overkill, for one thing (I recognize that this starts to suggest bigger changes to how Discourse works, I’m just pointing out some of the barriers that come to mind, setting aside how solvable they are as-yet). And then, what category would such content naturally go into in a typical forum? Would people be likely to browse a category that was dedicated to such topics? Even when they do, and even with a Topic Previews customization installed, they cannot view the images full-size without clicking-in, and they cannot react (like) without doing so either. This makes it more laborious for them to view and interact with these kinds of topics and thus decreases likelihood that they will do so. This higher friction essentially lowers the frequency of interaction, thus making the topics less popular, and thus likely disincentivizing people from posting them in a Discourse forum. Self-reinforcing negative feedback loop.
I would say, too, that an entire category of that kind of content is actually not of great interest to me either! This gets at a fundamental part of what is unique about social media feeds, I think. It’s less about Admin-driven categorization and structure, and more about user-oriented representation of content. And I think it’s critical to make clear that I believe that type of “shallower” content should not dominate any such theoretical feed, in general, but that intermixing it with other “deeper” content is potentially to the benefit of both types of post. Personally I am more likely to be excited about such topics if I see a couple of them interspersed with other things that I want to engage more deeply with, and conversely my brain also gets a bit tired of super in-depth discussion and/or reading consecutively, and a break of a sort with more “breezy” content would be welcome. My social media experience is sort of like that, except it’s compromised by A: the lack of control of what shows up in my feed, and B: the general orientation of social media content overall toward shallower engagement. The latter is a platform issue that I think Discourse might be able to solve while also better servicing that "shallower’ content.
Now, maybe one would argue that the “shallow” content isn’t “appropriate” for a typical Discourse forum. But hopefully you can agree that it, and many other types of related “shallow” (as-in depth of content and typical depth of interaction) content are very worthwhile, and worth promoting in the world. They make people on both sides of the interaction feel good. And the easier you make such “shallow” engagement, the more likely deeper engagement will also happen, either there, or elsewhere. If people more or less have to go elsewhere to get interaction on their small victories in life, they will do so, and be engaging on forums less. I, for example, was researching social media platforms because I wanted to set one up for my friends, since many have abandoned Facebook in recent years, and I miss the fun photo sharing and little commenting we used to do. But I didn’t find a single other platform that I thought they would actually want to use long-term, i.e. that would be “sticky”, and that includes Discourse. One of the reasons for that was indeed lack of a “feed” view and that quicker, easier type of engagement in Discourse (there are admittedly other issues for Discourse’s use in this context, but many can be gotten around).
So those are just some top-of-mind thoughts. If you want to do a deeper dive into the potential for Discourse’s use in a healthier social media-like context and the market potential for that, feel free to hire me, I’m a consultant. 
To be clear, I’m happy to provide a reasonable amount of feedback and ideas here (as I hopefully already do), this is more just about how much time it takes me to give thorough and thoughtful replies to deeper topics like this. 
I agree, and I don’t think anyone is suggesting that (are they?), nor am I even sure how that would be possible since Discourse works fundamentally differently from most social media in that the vast majority of Discourse forums are interest-based, more equivalent to e.g. individual Facebook groups than to Facebook as a whole. And “following” is basically a plugin and not native to Discourse anyway.
The “feed” would be more like “stuff you actively subscribe to”, at least as a first pass, and maybe optionally mix-in e.g. “related topics/suggested topics” (which Discourse already has logic/features for). So it could be more like a more personally-tailored “Top/Latest” view, really. It’d be great if long-term there was some “Follow” function that could also mix-in content from people you follow, I guess, but that could probably just become an aspect of the follow plugin that I think already exists.
That’s true, but is it every aspect of the feed that creates this? I would argue absolutely not. So then it becomes a more useful question of: which elements of the “feed” are useful/positive, which are negative, which may be closer to neutral, and which might we want to adopt? If some of the ones we are interested in adopting have negative aspects, what can we do to fix them?
For me personally, there are a couple of things I like about feed views. One of the biggest is actually surfacing entire pieces of (short) content and allowing direct interaction with them from a single screen. This makes the experience feel smoother and, yes, promotes quicker (but not necessarily less valuable) interaction, to some degree. I elaborated on some aspects of this above already. Another aspect is being shown novel but also likely interesting/relevant content based on simple signals like “Someone I follow made a highly-liked post that I haven’t seen yet” or “There is a new Tag being used frequently in topics that also have one or more Tags I already follow”, that kind of thing.
Good question. I don’t think so, and in fact neither does the classic example of the social media feed on Facebook either. Twitter sorta does this, which is one thing I arguably dislike about it. But Facebook does not, and I think it’s a better, more intuitive model, and more compatible with the long-form type of content Discourse tends towards.
Yes, quite possibly! Though would I’d really love to see is customization for the feed. I think that’s something that Facebook sorely lacks, in good part because they have a financial incentive not to offer such customization. They want control of what users see. Discourse in general wants users (or at least Admins) in control, and empowering users is definitely a core principle, with Trust Levels, etc. So I think some simple but useful controls for the user, e.g. check boxes for “include suggestions for additional topics I’m not following”, and “Include topics that people I am following have interacted with”, etc. would be great.
The more I think about this, the more it sounds like this could just be another type of “View”, like New, Unread, Top, etc. The distinction is, “this time, it’s personal”. 
It’s a whole new dimension to Discourse’s on-page experience, incorporating some existing capabilities (topic follow settings, suggested topics, etc.) into a new, user-customizable view. 