I see it as a reward for supporting Customers using the products, which benefits MS.
I don't see it as a reward for blindly supporting MS, if they need criticising then who better to do it?
Usually MVPs know the products inside out, often many products. They are well placed (because of the support work they do in the MS newsgroups, CIS forums, and here in UT) to gather user feedback and opinions and put that back into MS.
If you've been to a VFP conference and talked to Ken Levy, or Calvin Hsia, or any others in the team and got their email addresses from them - then you have a channel to the same people the MVPs talk to.
If you've applied for the beta program and been accepted, then again you get the same feedback into the product beta that an MVP gets.
FWIW, in my case, I was a Beta tester
before I was an MVP. I was astonished to get a call at work from Susan Graham asking me (huh me? little me?) if I thought a release candidate was ready to ship.
You don't get much more connected to the Fox Team than that (I know, join it!) and I wasn't an MVP at the time - so that could easily apply to other people too.