Any decent developer would be put off by any language to some extent.
Personally, I'm more put off by Rust than C (they put me off for different reasons). Currently, the one puts me off the least is Zig, but it still has many details that I don't like.
C is tedious but kernel programming isn't about spewing vast amount of code anyway. It is more important to be able to read it, understand it and ascertain it is correct. This is one of main reasons for why C++ is not there.
Except for, you know, all that Undefined Behavior stuff, which makes it practically impossible to write correct programs even for very skilled developers, or the lack of abstractions, which makes it hard to safely re-use advanced data structures.
"C is a simplistic language" would be more accurate.
Code is either clear and simple, or extremely obscure and safe, or kinda in between is complicated but not complicated enough such that its not safe.
"Simplicate and add lightness" aerospace mentality people like C.
At some point any project expected to do ever more complicated tasks, like a kernel, will be unable to use simple C and will have to take the hit of a more complicated language.
Simple is good when matched to simple tasks; my microwave oven or TV should ideally never data network with the external world and never malloc memory and never do string processing. C makes an amazing toaster or car automatic transmission controller.
Which one would you rather defend yourself with?
Call me indecent. I use C for firmware development running on small microcontrollers and consider it perfect for this particular task. Not put off by C for this task at all.
Why's that? C is a tedious language that makes you do so much manual bookkeeping, I don't think I'd ever write it again (if I needed C for some reason I'd write a program to generate it for me rather than doing it myself). I think any decent developer would be put off by C to some extent. Sure, the people who really want to make a kernel may put up with it, but an arbitrary enthusiasm barrier is not the way to attract good contributors.