While this shows Trump is probably a shitty businessman along with being an extremely immature person, I cannot blame Trump on this one. He did not write the laws that allowed for this abuse and given the opportunity to legally massively benefit from such laws. There's nothing wrong, as a private citizen, with Trump's availing himself of the breaks that the tax code makes available.Sad is it may be.
Now if his campaign had included identifying those laws as a problem and releasing his returns as a cogent illustration of what is allowed and should not be ...all might be good. But his tax plan includes nothing of the sort.
If you want to have a huge tax credit, buy a business, trash it, and sell it at loss. Or buy some really risky real estate, and sell that at a loss. Otherwise, it's just a matter of degrees. Or, to put it differently: If you suddenly realizes you could take a write-off that would allow you to pay no taxes (and it was totally legit) would you take it or not?
Loss carry-forward has been on the books for a long time. If there was proof that Trump personally had to lobby to keep it on the books, that might be interesting. Otherwise, not so much. This won't hurt him in the long run IMO. He's going to get hurt much more by late night tweets about "fat chicks".