The problem lies with talent and not time spent on/off the practice field.
True, there were sputtering offenses across the NFL but the difference comes down to which teams you think can get better, how much better, and how soon the change will start.
While I think the Panthers will get better, I don't think by much, and I think it's going to be a slow process. Dallas, NYJ, and San Diego however are in a completely different boat than the Panthers and should be on a steeper curve to success.
If you cannot see the differences in our team and their's albeit all in losses, I really can't help ya.