Those three compilers don't work everywhere, aren't allowed everywhere, and mostly works isn't "The standard gets pretty well-tested before being standardized as the most recent".
How were GC API, auto_ptr, modules, concepts and co-routines pretty well tested?
In those three compilers they surely weren't, so in which ones?
Most people are using more than one compiler at the same time. For instance, MSVC plus some combination of clang-based tooling for static analysis and/or local dev.
And folks using a full stack of MS tooling are probably using the EDG compiler as an implementation detail for IntelliSense support.
