There are an unbelievable amount of things to do in Las Vegas that doesn't include gambling. Many are free or very low cost. There is relatively cheap food and lodging everywhere too.
The downsides are the heat (great for night owls because it's cooler at night and everything is open 24/7), the crowds, and the crime of course. You can have fun, but you have to stay alert like one must do in any big cesspool, erm, city!