Unfortunately this is probably the case. Duhaupas was a genuine tough guy but he had nothing spectacular in his arsenal to help him win against the best. If he had a big punch he probably would have beaten Wilder who he lumped up big time anyway with his middling power. A real solid fighter but not a danger to the best of the division. In fact if he had had a big punch Wilder probably would never have fought him.
This is probably a factor as to why he lacked that edge. There are a lot of 'part time' pro boxers who suddenly become quite dangerous once they have full camps with proper trainers and nutritionists etc.