[cesarb]

> their proposal usually begins by proposing that it "should" be possible to just compile Linux as C++ software

That has already been done in the past. Quoting the FAQ:

"[...] the kernel was once modified to be compiled under g++. That lasted for a few revisions. People complained about the performance drop. It turned out that compiling a piece of C code with g++ would give you worse code. It shouldn't have made a difference, but it did. Been there, done that."

[pjmlp]

Yet the C compilers they use are written in C++.

It was mostly a Linus issue, and not wanting to fix what were the root causes of the regressions.