I see how the second part of my comment seemed like I'm asking for "Rust in the front-end", that was not my intention. My main point stands though, requiring Rust is not necessarily a "Con", it's in the "Pros" list for many people
It's off-topic, but it would be nice for someone to make a really good GUI toolkit for Rust. Something that integrates with system APIs for copy-paste and stuff like that.