It's simple, part of the community don't look further than the name of the dev and the number of pages of the thread. In the end, they all praise the same games, not because the games are good, but because they don't know what other games looks like. And if someone say the opposite in the thread, I wish him good luck.
I don't blame them, I've been like that myself. In fact we were all like that once ; we all praised Big Brother and Dating my Daughter... But we didn't stay stuck to those games, we looked at what was new, and in the end understood that we were overrating them.
As for Milfy City itself, there's no surprise in its success. There's somewhere, on this section of the forum I guess, a thread that was already praising the game, months before it started. Simply because icstor said that his next game would be on Ren'py.
They were already saying that it will be the best game ever made, before knowing anything about it, why should they change now that the game have had few updates ? Especially since they were already praising him when he was doing walk simulators on RPG Maker.