The trouble with warnings is every compiler has a different set of warnings. It balkanizes the language. Many D features are the result of cherry picking warnings from various compilers and making them standard features.
> It balkanizes the language.
Not really, as C has had even more diverse implementations per-standardization. I would say the situation is now, much less diverse under the rule of GCC and Clang. (Yeah MSVC also exists.)
I see this as a feature, not a bug. I compile my code with a range of different compilers because each one catches things the others don't. The creeping gcc-isation of everything is what I'd see as a bug.