They are discontented with how developers listed incorrect requiremente and how the game is poorly optimized on UE5. I guess they were holding out hope for a UE4 game. There's even a petition that has garnered thousands of signatures to have the game remade in a good engine. Obviously that won't happen but it shows how unhappy they are.

It's not really poorly optimized, it runs like any other standard UE5 game on my 2080 Super. No difference from other games at all. So it's quite hypocritical.