if they let everyone stand around there for a good 30 years, they created an implied contract. so when they just decided to kick you out for no reason, they violated their contract.

its kinda like at work. say you can only miss 15 days max. one year, the best worker their misses 16, but doesn't get punished because he is the best worker. then the worst worker misses 20 days, you cant punish them. by letting the other guy get away with it you created an implied contract which negates anything you have in writing. and yes, this will hold up in court.