there is a difference between liking a band "for old times sake" and thinking they're still making relevant music. I mean, I grew up in the 1980's too and I loved acts like Pat Benatar for example. But while I have seen Pat in concert before, I will be the first to admit she really hasn't done...
I think the dislike for "Van Hagar" is because they are so stylistically different than the Roth incarnation. Roth's Van Halen was a classic party rock band. Hagar's Van Halen was more of an arena rock band. Hagar had some good tunes with VH, but he doesn't compare to Roth IMO.