If they don't drink, gamble or have money for the shows ? This I've wondered often while living in Las Vegas.
I think I've seen most of what this desert has to offer.
I've camped  out everywhere, seen the hotspots, and even have my own secret 4x4 places.
It would take months to visit all of the casinos in Vegas.
In those months, more casino's would have been built, while the ones you visited would have been remodeled. 
Since we've been travelling, within a few blocks
- the Cannery (a high rise casino) was built
- The Nevada Palace was leveled.
- A Super Walmart has opened
- The neighbors that wanted to move got stuck, the ones that didn't got foreclosed on
- The roads that were under construction, with the cones and equipment, haven't been touched.
There's always something going on in Vegas.