C++ is generally used by millions of people to whom execution time matters quite a bit. The language is literally designed to force the programmer to decide how to balance CPU cycles with language abstractions and features. It's already hard to debug compared with a lot of other languages (which are generally slower).

The fact that you (and GGP) rarely encounter situations where run time is critical is a limitation on your experience, not a universal law that applies everywhere.

So, context is really important here.