Alastor fans don't have to clap like a seal whenever he's being smacked around but him actually encountering struggles he can't just smirk and magic away is a lot more interesting than him standing in the background for four seasons and suddenly going "omg I'm attached to this group of freaks". That was in fact the biggest concern surrounding his character prior to the show's release to the point where it became a running joke with the critics and it sounds like his fans who are crying now bought into that. Having Alastor have real struggles now will make it more satisfying when he overcomes them. And it's not like there still isn't room for him to bond with the hotel gang and for him to become torn between choosing them and what he thinks he really wants.
I don't know what's with the sudden resurgence of pilot-glazing, but the idea that you guys figured everything out about his character from it OR that his pilot writing is all that there is to him is pretty unbelievable. His backstory, that he just showed up one day and started taking out Overlords, is the same. And if they did decide "hey this isn't actually an interesting or compelling character to watch"? Then that's good. I was ready to write Alastor off completely and just wait for his "shocking" betrayal to come but now I'm actually interested to see what he'll do.