And relying on context means that there can occasionally be confusion that doesn’t need to be there.
Quotes aren’t automatic. People quote the post because they feel it was needed for clarity. It’s dumb to have that deleted out from under you.
But how often is it necessary to quote someone in the entirety?
But I don’t think it helped you enough in this case. 
How often is it necessary for the software to automatically change what is posted?
Actually, I’ve seen many instances here where posts would have made much more sense if Discourse had shown who was being replied to.
More than zero.
Just FYI, this is why full quotes are often necessary.
It causes confusion at times to not include a quote in a reply. (Not trying to single out any poster misbehavior here, just showing how confusion can naturally result without quotes, and why it’s such a terrible design decision for Discourse to remove quotes.)
I really wish the reply button would reply with quote. Does discourse have a separate button that does that, reply with full quote?
EDIT: Found it. If you hit the reply button, in the (blank) reply window’s toolbar, the leftmost button is a little quote icon. Click that to get the full quote inserted. A little hidden but functional. Much more usable than trying to manually select the entire post on a phone, which is why I didn’t originally quote. Selecting on a phone is a PITA.
Right on. 
Ran into some bizarreness. I just recently had a post where Discourse deleted my quote, even though the poster was not the most recent poster. And I had in fact trimmed the quote.
(When I edited back in the quote, I did change it a bit, shortening my quote, which I then thought should be separated out from Novelty_Bubble’s post.)