While I'm probably not totally un-receptive to some practical considerations of selection that keep the sport "healthy," I don't find making conference picks mandatory one of them. One, I'm not necessarily convinced that that makes a big difference in balancing, and two, I kind of don't care in any given year. I want a playoff populated with, by-and-large, only those teams on any reasonable person's list of "the best team in college football."
Back to the balance thing, I'm certainly not saying that that consideration is nothing. However, it's also true that I don't think that we're to a point where the upper Power 5 conferences (SEC, Big10, Big12) are in terrible danger of permanently eclipsing the ACC and Pac-12. FSU aside, what did people think about the ACC for a long time before Sweeney came along at Clemson? Not much. Years of the ACC and Clemson being second tier didn't stop Clemson from hugely overcoming that with the right coach. Ditto Oregon not too long ago (if you're old like me, you remember when Oregon was pretty irrelevant in college football....for a LONG time, I believe).
Who would be shocked if USC or Washington or UCLA or FSU or Miami or VaTech or Colorado, or......rose back to sustained prominence in the near future? And they'll do that without the necessary benefit of their conference's recent ("pitty"!) participation in the playoff. Harder? Maybe. But plenty doable....with the right coach.