Since it's a list of influential 90's bands with the restriction they formed and initially released in the 90's (I don't think Nirvana technically meets these requirements, although I believe Dave Grohl didn't join until '91 so I guess you could argue that), I think Weezer deserves to be in there, particularly considering their obvious influence on a number of pop-rock outfits today. The pop-emo sound of Fall Out Boy and other bands certainly owes itself to their influence. The worst part is I don't like most of the bands they influenced.
On that note, some people would argue Sunny Day Real Estate. I wouldn't. But, I mean, someone might.
What about The Red Hot Chili Peppers?
Certainly some worthwhile material released in the '80's but "Blood Sugar Sex Magic" really saw them hit their stride and is probably what the average person first remembers.
Offspring? "Smash" still kicks ass.
Sugar Ray? Smashmouth?
Man, what a decade!