It's. A. Beta.
Not a finished game. Still being developed.
This is like walking into a kitchen, taking a bowl of food that isn't ready, and complaining that it's under cooked.
There's going to be missing textures or placeholders. There's going to be performance issues. They will work that stuff out during the beta phase.
If it's not up to your expectations, then just wait until it's fully released.
Honestly, this is the chance you take when you pre-order. It's funny how many people are finding this out.
I guess the only argument here is that the developers should have waited a bit longer to release the open beta.
Because BlueSky has money and would sue the shit out of them for anticompetitive practices.