I can sympathize with people who didn't plan ahead, or who learned about the show only recently, but complaining about it is like complaining that you couldn't get tickets to a popular concert, or San Diego ComicCon, or any other event that sells out quickly. There's always going to be scalpers, and even if there weren't, the tickets they bought would have been scooped up by normal customers, and you wouldn't have been able to buy them at all. Popular events always require planning ahead, often far ahead. You don't plan a trip to San Diego four months before ComicCon and expect to get in. So what you do is plan a year in advance. Hamilton is no different, but because it's an ongoing, year-round event, people expect tickets to be more readily available, and that's just not the case.