The way I see it, It worked with WoW, why shouldn't they try it with their other games?

WoW players will need to merge their accounts to the new Battle.net soon. Right now it's optional, but in the future everyone will be forced to do so. We can only imagine why.

Blizzard's desire to support all their games with online capability, or in short, all their games, on a common online platform?

If you're selling and buying WoW accounts I'd understand that it'll be a problem (not saying YOU are, but I know people who do or have done so), but outside of that I can't really see what the big deal is (and of course, that's not allowed as per the license agreement). Personally I think it's great to have the same account for all their games.
Enlighten me, please.

I dunno, I just hate Battle.net in all its forms, I guess.

Well, just merge the account and be done with it. You can continue playing WoW like you've done in the past. It's not like you HAVE to be part of the community just because you log in using your e-mail address as username and play one game that uses the service (just like you don't HAVE to post on or read these forums just because you bought a game from GOG).
...not meaning to be rude, though I feel it may be interpreted that way, just don't really know how to make it sound different.

Totally agree with that. :)