Of course that's just my biased anecdotal observation, but I didn't notice ISU players slipping constantly and ruining plays.
While I presume what you're saying about the turf neglect is probably true, as it aligns with my past experience with capital projects at BYU and their ability to step over dollars to save nickels, I suspect cleat selection may have had as much to do with it as anything, and would explain why it seemed to be a bigger issue for BYU than ISU.
I heard some commentary that the players were wearing the cheaper version of the Nike Vapor series, which has a sole compound that was ill-suited to dealing with the turf conditions, which would also align with an ill-advised cost-saving measure.
Again, I'm no expert and I haven't/won't take the time to pull the game up and try and identify the cleats to corroborate the story/theory, but it's what I heard and wouldn't surprise me if both factors (poor turf condition + poor cleat selection for said turf conditions) were true and contributory.