You're correct in assuming folks don't spend much time writing positive reviews, and, while reading all the negative reviews, think about what exactly is being said. Many bad reviews are more toward dealers than they are towards manufacturers. The dealers are a liaison between the customers and manufacturers, and a first line for warranty repairs.
RV's require a lot of routine and preventative maintenance. There are folks who either don't know how, or, just don't realize what it takes to own an RV. Doesn't matter who built the unit, if it is not maintained, it will become unreliable, in a short time.
Travel trailers and fifth wheels don't have shocks, air ride, or motor vehicle type tires and don't ride as smooth as a motor home. Caulking will crack, plumbing fixtures, nuts and bolts, and screws can, and will come loose, through no fault of the manufacturer. You'll still see bad reviews about some of these things.