Qt's C++ heritage, I'd assume. That, and I really didn't like Qt Creator, when I last tried to play with it a few years ago. In addition, "package management" for libraries as per `npm` and it's ilk is a non-starter, though I believe there was something on HN attempting to fix that for Qt recently.
Qt's C++ heritage isn't any more relevant than WebKit's C++ heritage. I agree that the ecosystem needs to improve, but it's a bit of a chicken and egg problem.
