The problem is that familiarity needs to be maintained or you can lose it. As someone that doesn't get to use Rust at my day job that can be hard to keep fresh.

I only occasionally dabble in Rust in my free time and coming back to a project of mine after months of not having used any Rust, yeah lets just say that line noise made me prematurely murder some of my pet-projects.

Sure it gets probably better with time but still it is a cost that one pays.