I think the last time I went to a club at a hotel was in the mid-90s in the Baltimore area. A group of us had gone to a coworker's daytime wedding and were still in the mood to drink and dance. I want to say it was a Holiday Inn near BWI airport where the club was located.

As to why they're not around, I think it's a mixture of things. Socializing/Dating has changed since then (this club was also known as the local "meat market"). The liability costs have gone up (my cousins sold the family bar in the early 80s because they saw the trend). Customers staying at the hotel don't want to deal with that crap just like most hate when there's large groups staying at their hotel.