I agree with you to some extent. Whether or not the Council was needed is a different argument than whether it succeeded in adequately addressing those needs. Due to the laxity employed in the formation of documents, and the subsequent manipulations of those same documents to justify all sorts of aberrations, it seems in hindsight to at least be ill-advised. Most coming to the Council shared the same sense of optimism and devotion to renewing the Church. Unfortunately, a not insignificant group came with their own agenda, and achieved successful results. At least, the Fathers at future Counsils cannot claim to be ignorant of the liberal's tricks. They will have books like The Rhine Flows Into the Tiber to use as guidebooks for tactics to be on the lookout for. Knowing the liberals though, they'll come up with all new tricks by then.
I think some traditionalists overstate (and weaken) their case by making the claim that the Church before Vatican II was flawless and the state of the Mass in 1962 was the height of perfection. It should be readily admitted that certain improvements needed to be made, even if convening a "new type Council" to address these particular needs during the cultural environment that was the 1960's, was not the most successful undertaking in Church history.