[kragen]

Intellectually, the STL represents a significant set of innovations and a new way of designing reusable software, and it is an elegant jewel of design; the C++ standard library does not share those distinctions. If someone is having trouble with a software design problem in another programming language, it might be a useful suggestion to tell them to try doing it “the STL way,” but telling them to do it the “standard library way” would mean something quite different.

There's also the issue of credit. The STL is a work by Alexander Stepanov and Meng Lee. Conflating it with the C++ standard library of which it has become a part—or, worse, with a particular company's implementation thereof—has the distasteful flavor of plagiarism.