To some people a computer is a wordprocessor – they don't want Windows, they want Word, Excel or Access. That's probably why it makes complete sense to me that IE is an integral part of my Windows experience. Then again I've felt that way since the respectable half of the NCSA Mosaic team took over the IE project. If it was a strictly Microsoft application I doubt I'd have much tolerance for IE…
When you buy a house, you don't expect it to come sans light fittings, wiring, plumbing etc. So surely if Microsoft wants to be the sole vendor of software appliances for their operating system… Well, it is their operating system, isn't it? Why shouldn't they be allowed to call Windows proprietary and elect to be the only ones allowed to develop software for it?
This middle ground we live in, though, seems to be rather like an intellectual property racquet. Microsoft give you just enough rope to hang out your ideas on, and if they show signs of being profitable, they swoop down and crush you.
It doesn't have to be deliberate, it doesn't have to be malicious. It is just what Microsoft does. Either trying to absorb someone's concept that has become a "must have" operating system feature (and well meaning developers in Microsoft mean to implement it) or an MS employee sees a struggling product that just needs some money and wellmeaningly brings MS to its support crushing the team and finally the product.
As Operating System developers, Microsoft's biggest or at least influential customer, is Microsoft, which is terrible for Windows, because Microsoft are a terrible software developer.