> use a such a dangerous language that makes code blow up in their face?
There have simply been too many CVEs relating to memory safety in C and C++ software. It's not the 80s any more and we can't afford that.
If you aren't connecting to the network or running in any sort of privileged mode, the space of attacks that you need to care about is pretty limited.
Ironically, the answer to a lot of unsafe input in Rust is to crash (if your error handling logic didn't catch it), which is something that you likely care about a lot. Most players care a lot less about corruption of the internal state of your video game than they do about crashes.
EDIT: One fun fact here is that AMD never did the unsafe performance optimizations that Intel had to remove from their silicon. Spectre and Meltdown mitigations were instrumental in closing the gap between Intel and AMD.
But yes, having worked in service games for over a decade now, clients are treated as untrusted agents regardless. CVEs that result in control over local execution are mostly not interesting. At least for the purpose of maintaining the game; platform holders _do_ care, mostly on fears of piracy.
Galoob didn't cause revenue issues with Game Genie in the 90's. And revenue is the thing what matters.