There are two ways to take it, "Rust will never have a 2.0 ... therefore everything added to it must be perfect." or "Rust will never have a 2.0 ... so don't try to force it to be something that its not and lets make Rust the best it can be."

A language with Rust's priorities but designed with an effect system from the start could be epic. But Rust is not that language and maybe it can't be. And that's ok. We can give Rust a pass since effect systems weren't even invented yet when it was being designed.