Actually, yes they do on occasion. On several occasions, those GREAT Bama defenses gave up massive yards to TexAM, Ole Miss and others. Missouri had a solid offense coming in and Florida forced three-and-outs on their first six possessions. The Florida defense ended the half with back-to-back pick-sixes. That's pretty great.
Tennessee got super hot for a half, played their butts off, bolstered by one of the best home crowds I've seen in a long time, got Florida on their heels and blew their doors off. Tennessee was amazing that half, doesn't mean Florida doesn't have a great defense.