Well... speaking as a developer, "When is the next update" messages have never made me upset. I either tell them or ignore them, I don't know why anyone would let these comments out of any be the ones that get to them. Each job comes with it's own set of annoyances that you have to put up with. I am sort of playing the "they're getting paid for it" card, because no job is perfect. Waitresses have to deal with entitled customers, Streamers have to deal with trolls, Uber drivers have to deal with smelly people. If you deal with people, expect them to act like people and work around that. Prepare the ban hammer, prepare the febreeze, or just ignore them if you don't like what they're saying.Have you ever created anything?
Imagine you put hours of work into something and you get a message. You get excited, maybe its a review or someone wanting to say something nice about your work. You open it up....and its "when's the next update?". Nothing else, no compliment, no thanks, just someone shoving their hand into your face and going "gimme! gimme now!"
How long before you get sick of that? I've known a few people who have quit because the vast majority of comments they got on their work was basically "when's the next update".
And don't pull the "they should toughen up" or "they're getting paid" bullshit. Money is a poor substitute for someone going "Hey, I liked the last update. That character's story was fun! Thanks for it!". Getting paid and knowing you've done something well are two very different things.
Maybe I just haven't been spammed with these messages as much as your friend(s), maybe it's because I always give an estimated timeframe for a release, or maybe it's because this community informs everyone of when the update should be, but I can't think of any professional developer that decided to quit over the fanbase asking when the next update would be. It sounds like the devs who gave up after this just couldn't handle people. (which is odd for someone with aspergers to say)