Quality Time and the Television

Hoisted from comments, a la Brad DeLong, this from :

I also grapple with the quality time issue. Why is it quality time if I sit in the same room with no conversation surfing the web on my laptop while some mindless lowest common denominator crap is on the TV? VS me being a room away surfing the web on a better computer while not having to listen to the terrible tv I have no interest in watch is not quality time…I also wonder if it would still be quality TV if we were watching something I was interested in that she had no interest in?

And he follows up:

But somehow its become watching bad TV together is quality time together, which makes no sense to me.

I wonder about this myself… why is watching tv together quality time?