I feel like you're implying that would be a bad thing when it could actually be preferable. I don't think MS is faultless or anything, but I'd be surprised if they could make themselves as much of a pain as Adobe does (especially given all the OS integration opportunity).
I actually found out about Expression way after the fact and thought it was a viable alternative - but by then, MS was already in the process of sending it out to pasture.
It's like a co-worker said, "Adobe's software is bloated and cumbersome, but they have a top notch marketing team that keeps it afloat." But yes, if there is a company that is ripe to have some serious competitors it would be Adobe.