Not necessarily Vegas itself, but indeed the people of Vegas are pretty damn crazy. There are two main behaviours- sex and drugs. Sex happens anywhere and everywhere- on the streets, in bathrooms, on the stairs and not just straight one on one sex but gay sex, group sex and people just masturbating. When it comes to drugs, people don't even try to hide it. They will openly smoke joints in the casino, deal cocaine and shrooms in plain sight and it's all taken in as totally normal.
So no, Vegas isn't really that crazy, but the people are all pretty bonkers. To be fair, so would you be if you lived in Sin City and slept less than 4 hours a day!