I find this discussion quite interesting. I probably go against the norm in my arguments but I will explain.
My background is that I started on branded versions of unix (MAI systems boss vx/ux to be precised tho little references that now on the net). I think my attitude is totally different to alot on here in that I no longer go that route and sing along to the microsoft tune so to speak lol.
I know so many people that have gone the various linux routes - my own dad being one of them - I dont have a problem with that at all - alot of what I have to support in work in linux/unix based.
when developing software I do it for the mainstream (most clients are windows based so thats the obvious platform) but on the back end side of things I get left with do I go with apache or IIS.
I will go with IIS every time because it is supported, when using a microsoft technology agaist a microsoft platform at least I can get help - or to be a realist the answers to issues are more likely to be found online.
I think the key issues are at the moment is that whilst linux is omnipresent in many forms they dont and wont have the coverage to be able to support the potential user base.
Linux installs are so way advanced in some respects but the lack of compatibility is cripples them. I use both because I have to - but to talk between the two I need to install freeware or shareware apps.
Linux should be the way to go and it should be and easy choice. the reason it is not is cause it just does not have the support or functionality.
Its okay saying it does x x and x but when y comes out you cant do it till it is supported - its no good if your playing catch up.