I feel like this is a bad argument to be making. If a language's "level of suck" were based on its ability to write operating systems, then the massive boost in programmer productivity we see today from languages which sought to depart from that domain wouldn't exist. Tangential to that, I consider Rust a "fun" language compared to C++, and it is definitely capable of doing anything C++ can do[1].

By the way, Midori[2] was written in C#. Granted it had its own AOT compiler and started to diverge into a different language, but nevertheless, it was C#. I'd suggest looking through Joe Duffy's blog posts[3] as he explains it better than I could.

[1] https://github.com/redox-os/redox [2] https://en.wikipedia.org/wiki/Midori_(operating_system) [3] http://joeduffyblog.com/2015/12/19/safe-native-code/