There is some good rock in the 2000's. Alter Bridge, Seether, Three Days Grace, Staind, Breaking Benjamin, Chevelle, Tantric, etc. I certainly can't defend what he's saying about older music though. The 90's had plenty of great Rock; The Red Hot Chili Peppers, The Offspring, Pearl Jam, Alice in Chains, Foo Fighters, Nirvana, Stone Temple Pilots, Tool, Days of the New, Creed, etc. And of course the earlier decades have some great Rock.
Eh, Staind is decent. My stepfather liked Alter Bridge for a while but I never did. You forgot about the best ones from the 2000s though; Linkin Park and Muse, but they don’t save the 2000s being overal the worst decade in general since the ‘50s imo, by far.