I don't know. Maybe it is me. But I would not be a happy camper, especially with two kids. It would take more than a couple free drinks to satisfy me with a 90 minute wait. I have to imagine there are people like me. I normally wait at most 10 minutes to check into a hotel. 80% of the time I walk right up to an open person and check in. I would never expect a 90 minute wait.
Put 20 employees checking in people and it would move faster. Again, I will say, they have opened hotels before, they had to know this was coming since they know how many reservations they had. A big way to prevent this would have been up front only allow 30% of the rooms to be occupied the first night, then 60% the next, than 80%, then finally 100%. Then you don't have so many people checking in at once. So they could have done things, but they decided not to.
I realize this will fade and go away and most people won't remember outside of a couple bad reviews on trip advisor. But still I feel this should have been thought about ahead of time.