Guarantees are not pointless and are not always met, this certainly happened when Alea first opened and also ask the guys at DTD whether they are vital, they certainly have had some big overlay in the past.
In terms of poker Alea struggled in the guarantee war with Gala. Alea was a far better place to play and run better but didn"t really try to compete once Gala raised the stakes a couple of months after Alea opened. However I imagine the casino"s success or ultimate failure has little to do with poker but the fact that no gambling punters went in because of its location and the fact that the rest of Clarence dock failed