Saying it didn’t help them succeed at the next level is an assumption on your part. The number of things that go into whether they will be successful are numerous. Drew Lock not succeeding in the pros doesn’t mean Heupel didn’t help him become a much better quarterback, and his lack of success at the next level says little about whether Heupel coached QBs can work in the pros. Especially in this day and age where spread guys are succeeding all the time, this notion that pro style offense QBs are better is outdated.