I agree with you that the defense needs to be overhauled and I wouldn't cry if Capers found a new employer. But I don't know that Revis is the answer.
I would look at it slightly differently. When does that fire-zone, Steeler inspired 3-4 defense work? In the past, it's when you have some real Beasts at Linebacker and an outstanding safety. We have 1 beast, not 4, at LB. In Burnett, we have an outstanding safety..
Thompson went with the 3-4, in part, because there are more athletes who can fit the profile - there are a handful of Vince Wilfork types and many more great linebacker types. TT has not succeeded in his lower round picks on those linebacker types.