YOu have to be 21 to enter.
You are surrounded by people drinking, gambling, smoking like chimneys, and in a lot of cases being complete degenerates.
what exactly is family friendly about that?
For instance, you can stay at the MGM for $68/night from May 26 - June 8! My guess is, you'll find even better deals toward the end of June!
Plus, Las Vegas tried to be "family friendly" a few years back. Some properties (I think the MGM Grand was one) even built small amusement parks. That lasted a few years, but the casinos themselves realized that the two concepts--gambling/casinos and "family friendly"--didn't work well together, and they soon abandoned that approach.
If you want "family friendly," go to Disneyworld. If you want gambling, go to Mohegan Sun and Foxwoods.