Yes. In the portable music and mobile market it has tried to compete with Apple and closed shop many times --only in MS case it is called "canceled a project" or "closed a department".
As for the OS/API space, it has slided into irrelevance. Do you really need me to bring out the big guns and quote Paul Graham on this one?
"""Android is not selling at all"""
You seemed to have missed the "manage to offer knock-offs a couple of years later", part.
"""Amazon hasn't continued to gain more music selling share"""
You seemed to have missed the "manage to offer knock-offs a couple of years later", part.
"""no one is buying Kindles as there is the iPad"""
The two are not really in the same market. The Kindle is an ebook reader. The iPad is a tablet computing platform with ebook reading capability thrown in. There is a Kindle app FOR the iPad, for heaven's sake.
"""And Adobe was going to be in serious trouble too"""
With regards to Flash dominance in the future of the web (the only relevant metric, i.e. pertaining to Apple, in this discussion)? You betsa.