In the foreword to a book called "In search of stupidity", Joel Spolsky makes the case that the success of Microsoft owes much to the fact that each of their competitors did a lot of stupid shit while M$, mostly, didn't.
The article is a bit dated today, but I think he's still got a point:
For every other software company that once had market leadership and saw it go down the drain, you can point to one or two giant blunders that steered the boat into an iceberg. Micropro fiddled around rewriting the printer architecture instead of upgrading their flagship product, WordStar. Lotus wasted a year and a half shoehorning 123 to run on 640KB machines; by the time they were done Excel was shipping and 640KB machines were a dim memory.
The article is a bit dated today, but I think he's still got a point:
http://www.joelonsoftware.com/articles/Stupidity.html
For every other software company that once had market leadership and saw it go down the drain, you can point to one or two giant blunders that steered the boat into an iceberg. Micropro fiddled around rewriting the printer architecture instead of upgrading their flagship product, WordStar. Lotus wasted a year and a half shoehorning 123 to run on 640KB machines; by the time they were done Excel was shipping and 640KB machines were a dim memory.