Not that I disagree with your overall point here. But there are so many unknowns in your example that anybody turning down a big bag now on the chance to get developed for a second NFL contract is making poor financial decisions.
Miami is 5-0 and looks to be on a great trajectory, but let's not pretend that we are some surefire development factory. We might get there and I expect Belichick to flame out spectacularly at UNC, but his name still holds plenty of weight.
If Dopson is any good and Belichick leaves, he can pick up his fat sack of cash and look for another one with a team that develops.
Anyways, not directing at you specifically and I do agree with your overall point about long-term vs. short-term planning and also think Miami is a better spot than UNC, at least right now.
But if UNC is offering 7 figures and we are offering half that, he would be silly to turn it down on the chance that Miami gives him a better shot at a second NFL contract (which less than 50% of first-rounders get).