Arizona, what is the deal?

Okay, so the rv search has been completely interesting mixed with a whole lot of frustration and tons of disbelief!  So far, most of the places I've located on-line or called are for people age 55+!  These places all seem to have all the amenities one could ask for: multiple pools, spas, salons, shuffleboard, card games, activities calendars, ballrooms, etc!  What I want to know is why we are not allowed?  I love ballroom dancing, our kids are very well behaved and we mostly stay in when its hot anyway.  Every park we've been in, we've had great comments from management and they are always sorry to see us go.  We really try to take care of our spot, keep it tidy and clean.  Our kids do NOT run amuck and for the most part, aside from the occasional scraped knee or other non-serious injury, they are pretty quiet.  I don't get it!  Also, many of the places have outrageous rates!  Its ridiculous!!!!!  They charge a certain amount per month, then they tack on a lot deposit, electric deposit, application fee, extra person fee (for more than two people in your party), pet fees and then add to that whatever your electric is per month.  Then to top that off your rig has to be under 10 years old.  Yep, gotta keep up appearances.  Several of the places have to inspect it to make sure it passes muster before you can be in their park for an extended stay.  What?!?!?!?!?!  Its worse than trying to get an apartment!!!!  Thank you, Dear Lord, that there are those who aren't trying to price gouge!  There are several who have more reasonable rates and just happen to be kid-friendly.  Well, it is an adventure and we are really looking forward to being in that area, if we can find a place to stay that doesn't take us for all we are worth!:)  More updates later on the Will you let us live here? Saga!