I think it has minimal affect, but even some negative attention (depending what it is) can have a positive impact in terms of exposure.
Iowa is not a name brand program nationally, so it's not like some sort of reputation is at stake here. If a recruit is considering Iowa, it's because they've connected with the coaches and believe KF and staff have a long track record of developing kids and helping to put them into the NFL. Iowa is a respectable, clean program that does things "the right way." If a kid isn't looking for that, they were never considering Iowa in the first place.