For instance, I can’t have a post solely containing
[quote="Sam Saffron, post:1, topic:1, username:sam"] Welcome to meta, our official discussion site for [Discourse ](http://www.discourse.org). You’ll find topics on features, bugs, hosting, development, and general support here. [/quote]
despite there being occasions when a title itself is adequate.
I feel like this is intentional, so someone can’t just quote someone else’s reply.
User A would now be confused if User B is agreeing with them, or if they had a comment and forgot to type it.
Also, I feel like it’d be abused for character bypass. (Not like there aren’t plenty of ways to do that already)
Yeah, that limitation is fundamentally quite silly though - if someone wants to bypass it, they’ll just type gibberish.
I disagree, for bug reports for example, it’s a good idea to have a minimum to encourage more detail.
Also, it discourages, for example, a post with just a 
Or use zero width spaces, or empty HTML tags, or empty spoilers, etc. I get your point (bypasses will bypass), but still.
I believe that explaining a quote makes it more engaging to users than simply dropping it in.
I much prefer some extra context rather than just dropping a quote in. It is still possible to do if you onebox a post, so I’d actually go the other way and tighten that up if I could. 
Just as a PoC (Next post is a onebox):
As in, by posting a link, @JammyDodger? If that’s indeed possible, yes, that should be fixed whilst the rules remain in place. I do wish this rule was disabled by default, though.
I’ve run into the character limit a lot since working on external integrations, as well as AI Personas in Discourse. Often I want to start a topic or PM with only the quoted text, so a pre-configured API call does something with it.
I end up writing something additional, since I did not want to remove the limit on the sites I’m using. Sharing as a data point.