It was when they were going Bankrupt in the 90's. Before the new age of superhero movies. It's something they really regret, but then they had no real choice at the time. Besides if they had Spider-Man and X-Men we likely wouldn't have all the different massive franchises they've given us today. So in some ways it was a blessing.
But they are claiming back whatever characters they can get, and never letting them go again- They've already claimed back Hulk, Daredevil, Punisher and Blade.