Spinner9,
It is NOT discriminatory.
Have you ever seen well-dressed yuppies queued up to (perhaps) gain entry to a popular nightclub.
The "beautiful people" are passed through the velvet ropes, along with those with tightly folded large denomination bills to stuff into the "bouncer's sweaty palm. Nobody else.
Owners of private establishments (e.g. casinos, restaurants, theaters, hotels, taverns, etc) are protected by legal provisions based upon the Old English Common Law precedent of the "Inn Keeper's Law" -- that permits an owner of a private business to bar entry to anyone that they deem undesirable. It could be one's appearance or behavior or odor or ... The Owner / Operator is under NO obligation whatsoever to explain himself.
Last year I was, in essence, "86'd" by a local bank, pursuant to a quiet, civil, polite, (private) disagreement re: a charge for an overdrawn account.