Not the parent, but my own opinion is that if a C/C++ passion project becomes successful, it burdens other people with yet another source of security vulnerabilities.

This is even more so for small projects that didn't have the decades of security hardening of Firefox/Chrome behind them, and now people go to these projects assuming their security is on par with Firefox/Chrome.

Why is your imaginary burden more important than someone's passion?

I find Rust people to be really annoying these days if you can't even write software in the language you want to write without being a burden to society.