They're all right. But it's also exactly the problem with Linux in a corporate environment. For better and worse, Microsoft have made Windows a single, predictable entity. While we developers see the myriad of Linux options out there as the result of freedom, customers see them as evidence of confusion and lack of focus.
But I definitely don't see Windows as being tightly focussed nor a single predictable entity. The differences, nuances, and upgrade paths between 95, 98, ME, XP, Vista, 7, 8 are as fragmented and confusing as possible.
Linux isn't any better, this is true. But I don't buy that it's because of singular vision that Microsoft continues to dominate. Today Apple has the strongest composed experience, in my opinion. Too bad they have basically zero corporate presence.
This is perhaps because you know about the topic. The average user, because MS dominated most computer interactions that they've had, psychologically feels quite comfortable with it.
But I don't know if Linux is ready for the desktop yet. IMHO it's place is in the back-end.
Because Linux has more freedom it attracts developers/coders/programmers that also value freedom over vendor support. Any *nix flavor offers more hackability than MS.
And I think you'll find that the folks who use it think more freely when designing solutions as well.