What if no devs even tried to reproduce it, and they have no reason to believe they've fixed the bug with any other changes?

That seems to be the case described in the article. In such a situation, I think it's dishonest to ask the reporter to expend even more effort when you've spent zero. Just close it if you don't want to do it, you don't have to be a jerk to your customers, too, by sending them off on a wild goose chase.

Otherwise, why not ask the reporter to reproduce the issue every single day until you choose to fix it in some unknown point in the future, and if they miss a day, it gets closed? That seems just as arbitrary.