I hear ya on the atmosphere.... one of the reasons I love going to hockey games is the energy of the crowd.
But with football it just seems like there too many commercial time-outs which really slows down the pace of an already "slow" game. When watching at home you don't realize how long there is between each play because you see each play from a few different camera angles, slow motion, etc..... sitting in the stadiums lacks that for me.
To each their own.
Edit: quick side note..... both my dad and brother are big football fans and really have no interest in hockey. However both of them have been to hockey games (more so as social/family events) and have had great times and like going back. So though they don't enjoy watching on TV, they're all about seeing games in person.