I'll agree that Prohm's in game tactics have not been great, but I think both of these situations are different. Against Ohio State, we were playing good defense, but weren't putting up points on the offensive end. Even though Wesson had a pretty good game, we were fine with him getting his as long as we weren't giving up easy shots to other guys. Had we even played okay offensively, we would've won that game.
Against Purdue, we went big because Purdue started a 6'10" PF and a 7'0" C. Prohm made an adjustment and it worked, however we fell just short. It's overly simplistic to say Steve could've made that change earlier. We had a lead towards the end of the game and Purdue ended up making big shot after big shot.