This is a volunteer project, and as such, developers are allowed to work on whatever they feel most fun working with, all of this with its advantages and disadvantages of the thing.
Also, LucasArts games are currently being worked on more than you would expect: there has been a SMUSH font rewrite last year which makes it pixel perfect, there have been lots and lots of fixes in the walk code for every single major SCUMM version (from v2 to v8), v7-8 font drawing routine is currently in the process of being overhauled with a version which makes it pixel perfect and which correctly wraps text, COMI sprite decoding routine saw a major bug being fixed, and don't even get me started on iMUSE...
I do understand the frustration in seeing that developers apparently neglect or forget old bugs, I really do: I was one of those
1) it's simply not true that they are not working on SCUMM games anymore, it's just that every major developer is working on at least two engines at once, so (being an after work activity) they might just not always have time to deal with them;
2) if you are upset about a certain bug, maybe an ancient one which nobody seems to care about anymore, do what I did: learn how to do it, and do it yourself, because if you really are the only one who cares, nobody else is going to do it for you! I'm serious, not being sarcastic, insulting, or anything! It can be a good learning experience and rewarding for sure.
Also, about this: I can see how from the outside the attitude might seem a little cold but rest assured, that is how pull requests usually work, after all they are just requests for code review for a new patch.
Of course most of the comments are going to be request for fixing syntax, memory leaks, and whatnot, but that is to be expected: the project has to maintain a very high code quality since the application is actually used to ship games on Steam/GOG nowadays.