Okay, let's get this out of the way right off the bat. That headline is hyperbole. I don't think one man could possibly ruin the entirety of rock and roll. That takes the combined effort of a movement, such as hair metal in the '80s or nu-metal in the late '90s.
Danger Mouse isn't a movement. He is, however, representative of an increasingly aggravating and desperate production trend.
Danger Mouse hit it big early in the '00s when he did that original mash-up of Jay-Z's Black Album with the Beatles' "White Album" to make the Grey Album. Speaking for myself personally, I never thought it as a particularly inspired idea and I never liked the mash-up trend to begin with. Perhaps for the novelty though, it spread like wildfire across the Internet, especially because the record companies got involved and made a martyr out of the Mouse.