The field was so bad the year before we went to turf. I don't think our team has personally seen an uptick in lower body extremities since it's installation, but I'm just going from memory and not stats. I think turf has come a long way since the 70s, and supposedly they're working on some kind of hybrid called frankenturf that's a combination of both.
I like a grass field personally, but I also acknowledge that it's difficult to maintain in the northern Indiana climate. It takes a lot of work, and even then the results over the season can be ugly. There are options for grass today, like what Real Madrid has. They've got retractable fields and underground greenhouses to help protect it from the elements. That would be a shit ton of money though, and I doubt ND would pay for such a thing.