I think the main thing people have an issue with is partnering with MS and using their platform rather than buddying up with Android or persevering with their own stuff. As you point out, and as they have publicly admitted, sticking with their current platform is proving to not be a viable way forward.
The apparent indignation at them choosing MS is, in many cases, a bit of fanboy-ism. The average man in the street won't care, and those of us who would particularly prefer Android over Windows just won't be buying a Nokia phone in the near future, which depending on how big a demographic we are they may not care about.
I think going with MS makes more sense for them than following the Android path, despite my vague allegiance with the Android camp. If they went that way they would just be another Android phone manufacturer which could work well if the hardware is good and competitively priced, but by going Windows which is a small part of the market now they have a chance of being the leader of that pack if it grows to be the preferred alternative to Apple's output. And it may yet manage to become a bigger player than Android - the Windows phone platform has the advantage of not having any association with the many cheap and grotty devices that are being shipped with Android (this association could tarnish the public view of Android devices on the whole).
> It's like those people still using Windows XP because it's the best.
But always remember that there are people like me who are still using XP because they have no particular reason to spend money on an upgrade. No DX10/11? Not a problem, the games I do play (including those released in recent months) seem fine and if it became a problem (games requiring later versions of DX) then I'd just find something else to do with my time. IE9 won't work? No problem - the only thing I use IE for VMWare Server's console (which has issues with FF and C) and for is downloading Firefox or Chrome.
I'll have to upgrade in a while because security updates will stop. But until that time I'm unlikely to have reason to spend money and time on changing OS.