If I may interject...
I was one of those who said (not on this forum, but in the proper real world) that I feared Psychoville would be unmitigated shit. The reasons are simple. 1) It has been sold as a dark and twisted world of murder, mystery and weird goings on behind closed doors (League Light). Some of the character descriptions sound like they were left-overs from League writing sessions that didn't make the cut. Having seen the preview, I can say only Reece's clown really fits that bill.
2) Face it, the stuff Steve and Reece have been in have been mostly shit. Even Reece was making fun of Benidorm! Jeremy and Mark have diversified with their writing and taken on different genres, so to see the other pairing return to extremely similar territory after all this time was a bit worrying. As I said, it sounded like League left-overs.
Oh, and I do think Eddie Izzard should progress, or at least learn that 'jam' has its limits as a punchline... Watch Ross Noble for a far better approach.
3) The blackmail plot linking characters together was an original idea for S3, so it really really REALLY sounded like left-overs!
4) The title is crap. It's like how someone would spoof League and other 'dark' comedy.
However, the good news is that having just one pair writing together has made a big difference to the structure. It all fits together and flows much more nicely than S3, it feels like a unified piece. Casting other people in roles so they don't play them all themselves has allowed them to stretch as actors and for instance the writing for the dwarf characters is wonderful.
As for you moaning that fans shouldn't have such a pessimistic view, well, bollocks to that. I don't trust the view of a fan who thinks absolutely everything a group has ever done is brilliant. That's not love, it's obsession. When someone adores their stuff with a critical eye, then that's truly worth something, because it is a carefully considered opinion and not a knee-jerk reaction.