It's not a 'good' thing, it's just a legal thing. If it was legal, it shouldn't even be a story.
Oooh, a business wrote off losses! They never do that, except, yes they do. All the time, and if that loss is large enough it can be carried forward. Again, it is extremely common.
Why? Because it's perfectly legal and ones accountant would have to be beyond incompetent not to take such a common write off as a loss or carry it forward until it was fully written off.
Look at some of the other large corporations out there. See what %, for instance, GE paid over the last decade. Anyone taking jeff immelt to Task? No, in fact he was head of the President's Council on Jobs and Competitiveness. That was a joke on more levels than one, considering the amount of offshoring that company was, and is, doing, and their history on taxes, but that's the fact of the matter.
I've said repeatedly that i think it sucks that the laws allow this sort of dodging, but they do. The problem is in washington, not in trump's tax return.