After yesterday's Dez Bryant fiasco, this is a rule I would strictly enforce if I was an HC. Unless it's 4th and goal, it just isn't worth it. So many of these guys are getting the ball punched out, or fumbling it through the end zone it seems. RJ 3 had it happen against the Giants, and Sammy almost did the same thing against the Phins, just to name a couple of examples.
You can tell that's what Dez was trying to do, rather than just secure the catch.