I like RPGM games that have no fights, where you mostly explore, do some tasks and find scenes around. I like the feeling of being active, the reward for finding a scene (and even the feeling of losing scenes due to not finding or doing something, which makes me play again and again), activelly choosing to go somewhere and corrupt someone and all that. The freedom is enticing.
As for Ren'Py VNs they are very linear and passive. Even the ones that have choices feel very weak and boring, not exciting or rewarding, and usually have too much (normally) bad written text that I personally don't want to read. There's a balance between exposition (reading) and gameplay (like exploring) for the game to be fun and have a good story telling and I feel like most ren'Py games lack a lot on that front.
That being said, I don't go on Ren'Py VN threads to complain about them being Ren'Py VNs. I don't want to offend, but it's annoying to see people complaining so much on RPGM threads. Can't you guys let people who enjoy RPGM play it in peace? You can always not play a game if you dislike the engine that much, you know? No one is forcing you.
Anyway, good luck to the developer, I'll follow the development, it seems promising