I think most busnuts are older simply because they have more time and money once their kids are raised. Most people in their 20s and 30s are more worried about getting married, raising young kids, and getting established in life. RVers tend to start with travel trailers and then move up if they enjoy the lifestyle and have the funds.
I was lucky and built and sold a business for a significant sum of money before I was 30 years old.