Every coach teaches their defensive line to get their hands up. That's not an "Iowa philosophy." Not all tipped passes are tipped by defensive linemen, or even defensive players at all. Are you suggesting Parker calls a "have the ball bounce off the WR to our safety" play? Or a "have our DE deflect the ball to our cornerback" play? That's what it sounds like you are saying.
Acknowledging the fact that tipped passes are unpredictable does not detract from the fact that Iowa has a good secondary. Iowa has a good secondary. They would have a ton of INTs even if every tipped pass hit the ground. Because they are good. Iowa's defense is good regardless of the fact that they seem to catch some breaks. Every team has an expected range of performance. Iowa's range is higher than most on defense and secial teams. This year both of those units are playing at the high end of that range. That's also an aspect of luck.
When Iowa catches breaks, as they are this season, they are playoff contenders. When their luck is "even," they are an 8-9 win team. When they have bad luck, they are a 6-7 win team. That's a hell of a program. It will be interesting to see if it can be maintained once Ferentz hangs it up. Too bad the fanbase is such a bunch of insecure *******.
The "luck" I'm talking about is more than just turnovers. It's also things like having great special teams synch up with great defense, so your traditionally okay offense doesn't limit the team. Not suffering injuries. Not getting targeting calls (if you don't think those are random, you don't watch enough football).