I never had an Xbox until Xbox One so BC was a key feature for me and it has been great. Not every great past game has made it to PC and not all of them have made it to One yet, but plenty have and several of the really good ones were even massively enhanced. Some old games are even better on Xbox One than they are on PC due to crappy PC port stuff that never got worked around.
But BC is that important to me, that I would gladly do it.
I love playing games like Oblivion, SSX3, Banjo Nuts and Bolts, Soul Calibur 2, Sonic Adventure, Sonic 3, Ninja Gaifen Black, Perfect Dark, Halo Reach, and Hard Corps Uprising.
I believe Sony is really testing the waters for how little effort they can put in and still be profitable.