Of course I know that questioning my own opinion is always healthy. So, if you have some reliable sources telling that the majority of the visitors of Las Vegas-style casinos are very rich people, or "crème de la crème", as you put it, I'd love to see them
What do they say, seeing is believing?
Have you been to Vegas? I've never been to Vegas myself, but I've heard stories from people that were there couple of years ago. It's from them I learned about the common misconception regarding the average crowd in Las Vegas. Going there they were expecting to see what they saw in the movies, the elite, the crème de la crème. But in reality they were constantly encountering people who were looking more like rednecks and such.
Also, I've found an article on Quora with street photos and one pic inside a casino, from which you can get an impression on how the average visitors look in Las Vegas. Here's a quote from the article:
Your impression of Las Vegas must come from TV & the movies only. If youd ever been to Las Vegas, youd know that most of the tourists there are not rich ...
I know it still proves nothing. But what I failed to find is a single article telling that only rich people visit Las Vegas.