BunkHouse RV's, why so many more TT, then Fifth wheels?

I've towed both a 31 foot TT and a 34 ft. 5ver. Properly set up, I prefer towing a TT. When we had our 5ver, it was a Cougar bunkhouse model. Our kids loved it b/c they had their own room with a door, storage, and t.v. The bunks were also oversized - important for older children.

5vers tend to be more expensive than TTs, and a bigger truck is usually needed. Growing families often can't afford this, IMHO.