It has some very useful principles, but also some super-annoying gaffes and mis-design aspects. One example: Allocators. What a mess! Or the fact that if a map lookup fails, an exception is thrown. I can't count the times I've had some app just bail out on me with an at() exception, because the author neglected to handle it (and the map/unordered map interface did not force them to). That does not detract from Stepanov's important work.

The kind of programmer who don't check (or think through so that they can't fail) their map lookups is also the kind of programmer who don't bother with const. What a non-const unchecked map lookup gives you is a default-constructed value that has just been inserted for the only reason that operator[] returns a reference, which must "point" to something. That's bad and can be confusing, but it doesn't crash.

I see that problem much more often than crashes due to unchecked map lookups in production, which are very rare for me. Less than once a year.