But many of those valid criticisms require some familiarity with the language. With syntax they can just point at it and claim it's bad without having to learn anything first.
I mean I have worked with c++, Python, JS/TS, Java and Scala. The syntax of Rust is a mix of these. Apart from that, borrowing, some pointer work and you're set. Honestly Copilot is pretty good at generating code that you can pick up the patterns from. I would highly recommend you give it a try. Not a fan though, for any large project Rust wont be my first choice because of lack of proper libraries and Java is performant enough almost all the time.
Just the syntax is miserable punctuation soup to start with.