[orwin]

Its not really a bad choice, but writing really good c++ is hard (sightly less with the newer versions, but still). You can use the same performance tricks that a C dev will use to make your code faster, plus a whole lot of new tricks, some doing exactly the same thing (but not the same way). This is not a problem if your team is used to work together and have a common codebase they already wrote together, for for OS project (like linux), its a bad idea. And in my opinion, writing optimized c++ code is waaaay harder than writing optimized C code (almost each time i had to optimize c++ code, it ended looking like c with classes and weird pointers)(Disclaimer: i'm bad with OOP, it might be just me).

Anyway, Google is supposed to have good c++ devs, with experience coding together, so this is not a problem for them, i think. Another issue is that the compilation is slow compared to C, but i don't think its an issue for Google either.

[edit] Yes, binary size can be a problem too, forgot about that. But if you only use basic libraries, i don't think your binary will grow that much, right?