Get real. IE is must have if you're a web developer. Last time I checked, IE was still over 50% of the web. Web developers still need to check their website in a bunch of browsers--including multiple versions of IE since a lot of users are stuck on IE 7 and 8 for whatever reason.
I'm not a web developer. Nor do I use Windows at home. I guess your point is that in the enterprise or web developer industry, you need Windows PC, I can totally believe that. Also, if you are an aggressive gamer, you will probably be more happy with a PC than a Mac. If you are outside of those areas, you'll probably be happy with a Mac or whatever else you want to use. If you are a consumer/non-gamer, then it doesn't really matter unless you are into Office; I mean, the must have apps are already on the web (facebook).
There were several programs in my college classes (enterprise bullshit) that I needed IE to run. I didn't say it was a good thing, but that is the way it was.
Visible Analyst 2008
Net Weaver
SAP client
CoD Black Ops
CoD MW3
Insert tons of other video games
Internet Explorer
And that is just what I personally need a copy of Windows to run.