Same reason I always wait- once you are booked without an offer, no offer will come for that time.

I can't remember if they have a first time at the property bonus though. A lot of CET properties have some sort of bonus if you are an existing TR card holder and visit the first time. I know Reno gave me some sort of food credit my first time there, Ak Chin would give some small freeplay and a free buffet, Rincon gave me freeplay, etc.