I argue that the issue is that now the "anti-DMCA" crowd and issue that had been built up looks "satisfied" when Congress comes to look at that issue, as there is a more effective solution at hand to what had been placed at the core of their debate. It isn't that comex is saying "damn, rather wouldn't have this FCC rule, as the rule itself might be negative" but more "damn, the end result of this entire fiasco might be negative".
2) Because of #1: Don't let the perfect become the enemy of the good. This is a good interim solution.