No one wants to knock the idea of building a better mouse trap, but there are different ways of defining better. Rust might well overcome shortcomings in C, such as the ability to write technically correct code which creates chaos at run time.
However, anything new has to fit into the existing world. Beta video was technically superior to VHS, but VHS was established first in the market place and Beta couldn't compete with the investment tied up in that slightly earlier technology. Both were eventually superseded by DVD video etc, but that happened for two reasons:
1. DVD was sufficiently better than tape to justify consumers buying the players, and
2. The big money investment was in celluloid which could as easily be copied to one format as another.
Powerful people don't like the truth. They want the world to fit their wishes not reality. I have ruffled Cisco's feathers by pointing out their assumption everyone will just fall in with what they want and adapt to continue using their product, rather than just walk away and find something else if that adaptation's too onerous, is a flaw in their business model they don't want to see. The market doesn't work like that. People won't necessarily jump over barriers suppliers put in their way.
Until someone writes an entire OS in Rust with an API compatible with existing software, C will be here to stay.
Yes, I could configure
ports-mgmt/poudriere to use a binary package, but the joy of Poudriere is the fact it builds packages for me while I'm away from my computer so they're ready for me to install when I am. If I have to start implementing workarounds for individual packages I lose a lot of that simplicity. There may be times when I have to do that but, on this occasion, it's not worth the effort.