For personal projects, I use C because it is fun and brings me joy without getting in my way, while Rust brings me pain, and (when i must seek help) derision from the community. Here, I choose fun and joy.

For work I use C because that is what all existing non-toy kernels are written in and will continue to be written in until long after i've retired, been buried, and decomposed. Here, i choose what employers want and will pay for.