Having an integrated environment isn't a bad thing, in and of itself. The problem with most IDEs is that they lock you into their way of doing things. The project/solution config and setup are all specific to the product. This makes it difficult, if not impossible, to seamlessly change from one to another.

It's understandable from a companies perspective because they want to make money. If you, as a developer, can easily change products at will then they can't maintain a dedicated income stream. But IDEs are, and should be seen as, tools. It doesn't matter what brand of screwdriver you use so it shouldn't matter what IDE you use, either. Products should compete on features and usability rather than lock-in.

At least that's my opinion.