First, the program he took over was not nearly as moribund as you suggest. IU was 5-7 (including a win over Purdue) in 2010, and was a dropped wide open Damarlo Belcher/sure TD pass with 28 seconds left from beating No. 15 Iowa, winning six, and going to a bowl.
Next, if verbal abuse and ridiculing injured players equates with toughness, then yeah, I guess you could call Wilson tough. His head coaching style might have worked in the 1980s but not in the 2010s. Today, it's the stuff that scandals and litigation are made of. You'll never see Mr. Tough Guy in a HC capacity again, at least not at the P5 level.
Under Wilson, legitimate toughness was sometimes in short supply. The most gut-wrenching loss I've experienced as an IU fan was the 55-52 loss to Rutgers, in Wilson's fifth season. You'll remember IU was up by 25 points in the third quarter when our players got complacent, started yucking it up on the sideline, and stopped playing. That's clearly reflective of a lack of discipline - - and toughness. The result was a shocking defeat and the end of thoughts of a glitzy record and a truly special season. There are numerous other examples of dispirited, lackadaisical play during Wilson's tenure. And, at the end of the day, it's all about results. For all of his so-called toughness, he never produced a winning season.