The community spirit and sense of togetherness at Woodstock was a one in a generation happening, and couldn't be replicated. People tried to organize follow up Woodstock events, under the original name, in 1979, 1989, 1994 and 1999. The last of those ended in complete disaster, as violence and riots claimed the festival, resulting in large fires, uncontrolled fights, and absolute anarchy. You could still argue that nobody suffered worse than the original organizers, though.
By now, you've probably realized that receiving no ticket money, plus paying the bands in cash, plus having to helicopter the bands in, probably cost a lot of money. You'd be absolutely right. By the end, the four organizers were in debt to the tune of $1.3m. Paying that debt off took them over a decade, and it was mostly done by licensing audio and recording rights from the festival. Thanks for picking up the bill for us, guys. We appreciate it.