Late reply, but better late than never, right?
Erm, no, you do have an “aesthetic opinion”. It’s just a “simple” one. But don’t make the mistake of believing that is “not much of an opinion”. The same way that not “making a decision” is in fact a decision in itself. 
And the very fact that a judgment call must be made as to what constitutes “simple”, or “not much of an aesthetic opinion”. I realize there are arguments you’re making that are partly technical (e.g. no drop shadows means a less complex CSS definition), but you can’t ignore the resulting design aesthetic that comes from this, and it is “opinionated” in its own way.
I don’t exactly see how, with the existence of a powerful theme system and a variety of base themes to choose from, having the default be “fancier” (or more opinionated or whatever) really makes it harder for people to customize.
But before I bury the lede, I’ll just say what I came here to say: Wordpress provides a new default theme frequently with their major versions. This does two critical things that I think Discourse would highly benefit from (especially the second).
- It provides an opportunity to highlight new functionality from a design perspective.
- It means that all new Wordpress installs will look newer, different, arguably more current and thus perhaps even “better” (depending on your preference, hah).
Discourse’s design looks a bit “outdated” to some not-insignificant subset of admins/community builders and users. Updating the design on a regular cadence, perhaps with each major-minor version (e.g. 2.8, 2.9), or at least every few of them, could be really beneficial for Discourse in a variety of ways.
- Keep Discourse looking modern and fresh out of the box for all new installations
- New designs can be marketing/PR tools/events, both actively (“Announcing our new Discourse theme!”) and passively (visitors to forums that update default theme, or are newly installed, or seen on Discourse.org, see a more modern design that compares more favorably to other current tools)
- Developing new core theme iterations internally might help the team better identify work to be done on the theming system or other core systems, vs. the more casual approach to the many (appreciated!) themes that core team members do already create
I think the regular core theme updates/releases have a lot of potential benefit. And I’d love to see Discourse consider doing something similar. I recognize that updates are made to the core theme, of course (e.g. new PM styles), but this is a different approach that I think has unique value.
and your feature request is fulfilled.
, food, recipe pics, fitness etc. … a few suggestions from a few niche areas that need a gallery as well as discourse in words.
: probably don’t need one.