There are more single te sets than there are double te sets.
If we ran double te sets everyone would complain we kept running the same plays.
Fant was going to get covered by the opposing teams best. If he could draw a double team, great, but only great if that got someone else open. If not we not only sacrificed our te (and he wouldn't of had more catches or TD's anyway) we would have lost even more plays because Nate might not of had anyone to throw to.
It's like a game of chess and if you don't know how to play, you don't tell someone else what move to make.