Clemson only had two losses in the regular season, and those were both to ranked teams.
Notre Dame and South Carolina both had four losses, and two of them in a less than spectacular manner (Marshall and Stanford for us).
Thus, Clemson did deserve to be ranked up there. They won the games they were supposed to win, and we didn't.
Are we a better team than Clemson overall? Probably so, but when you lose the games you're supposed to win, then you deserve the fate that you get. If we would have beaten Marshall and Stanford, we could have certainly had a NY6 bowl berth. If we would have beaten just one of those two, it's still possible that the NY6 bowl berth could have been in play, even with the USC loss.
We controlled our own destiny, and we didn't make it happen.