In Programmer Hubris Part 1, I described that frequently I'd come across applications that impinge on my consciousness far more than is justified by my infrequent use of them.
I expressed it rather simply as "I'm just not that into you". You, the developer, may believe that your app is the most important thing in the world – to me, it's something I use once every six months, and not because I want to. Don't give me even more reason to remove your application.
Maybe Microsoft gets this, because they've just released "Windows Principles: Twelve Tenets to Promote Competition".
Some of the highlights relevant to this topic:
1. Installation of any software
2. Easy access
4. Exclusive promotion of non-Microsoft programs
I also like:
9. No exclusivity
10. Communications protocols
Go and read the document – I hope to hold Microsoft to these principles in the years to come.