I should have phrased it less strongly to say that Google doesn't have broad Rust experience AFAIK. I know nothing about their decision making process and the t

I should have phrased it less strongly to say that Google doesn't have broad Rust experience AFAIK. I know nothing about their decision making process and the trade offs involved, but if I had to make an unprivledged wild guess I would say the main factor for C is the ability to leverage experience building similar systems in C inside the company, and the amount of prior art outside the company written in C as a close second reason.