For the same reason as people were rejoicing when Phil Zajicek was finally brought down. Rogers has had too many fingers in too many pies and it's been more or less common knowledge that he's shady for almost a decade. This is "Ferrari" Mick "Freiburg" Rogers, who Sinkewitz attested to visiting the clinic where T-Mobile riders were getting blood boosters on TdF rest days, and who Leipheimer's affidavit in the Reasoned Decision explicitly fingers as having been visiting Ferrari for training plans along with those known crusaders for clean cycling Alexander Vinokourov and Andrey Kashechkin. This was at the time when Ferrari was banned from acting as a physician or pharmacist specifically because of his actions in the doping of professional athletes. This rider has then been a key component (road captain) of a dominant train of cyclists that aggressively touted their cleanliness at all opportunities while putting out higher power outputs than he ever did at T-Mobile or while a Ferrari client. Seeing a rider with his history then boasting of his power outputs and cheerfully telling his teammates they can ignore attacks by GT winners like Evans and Nibali based on the power he's putting out makes it seem doubly appropriate that he should finally be busted.
Of course, there is still a good chance that he may have been innocent on this occasion, but as hrotha already pointed out, given that we know Rogers has been cheating at least at some point in his career for the best part of a decade, good riddance to the guy. I thought he was Teflon, so I'm glad to see I was wrong.