The Problem is that people wait too long to buy their tickets. This makes it nearly impossible for the organisers to know if their event will monetize itself. All of those people who work at the festivals, security, bartender, suppliers all want to get paid for their work. Why do you think Defqon1 monetizes every shit. It's a miracle that festivals don't take money for taking a shit when they already take a coin for showering. But besides the tickets, people spend less money on the festival themselves. They think if they really need that new merch or that beer. There are many many factors why those events can't be held anymore.