There is a reason that these hotels have rules and policies and trust me, we as guests are much safer and better off because of them.
Every AI is the same, noone past the door without a wristband. Makes sense to me! Though it gets frustrating when I am meeting someone who is staying at an AI and can't even enter the lobby to call their room. But, it is the way it is and I have to agree with their policies. It would be very easy for a guest with a wristband to go to the bar, grab a pile of drinks and share with someone who has not paid their fair share. If you really want to bring someone into the hotel, you can pay for a day pass wristband, price varies from hotel to hotel.
Oasis is definetely a hole. The grounds are great but the rest of the place is horrible and not worth your money. If you wanna party there just stay at the oasis viva for less money and you can go over to the oasis for free.