[BeetleB]

The problem is that everyone wants something different in an IDE (and the same person often wants different stuff depending on the language they are programming in). Whatever default Emacs can provide will be suboptimal for most users and cause additional dissatisfaction. People have a more open mind when when they know it doesn't include an IDE and may have to work to get one up and going than if they simply see the default one and think that's the best they'll get with Emacs.

To give you an idea, I used Emacs as a programming editor for a decade, and only about 2 weeks ago did I first set it up as some kind of IDE (or rather, I just installed elpy and it did it all for me). I was perfectly happy without using it as an IDE - knowing the constraints that come with it.