Why RV?
There's just so much to see that we want to get out there and experience it with our kids. I never really went anywhere growing up, so I feel like I have a lot to make up for in my own life, and I want it to be different for my kids.
It's too expensive for a family of 5 to stay in hotels. Plus, the food cost when staying in a hotel is outrageous! It's impractical to carry coolers into your room, then you don't have a proper place to cook. It gets very expensive, not to mention unhealthy, to eat out all the time.
I figure that my friends that take 1 week long vacation per year to Disney spend about 5K for their family of 5, including air fare. 7 days doesn't seem like much return for that much money.
For the same amount, I can make a year's worth of camper payments and insurance, take 2 or 3 week long vacations (including gas and camp site fees), and 7 weekend trips. Definitely more bang for your buck!
We could tent camp, but having a fridge and everything we need in the camper is worth it's weight in gold.