There gets to be fewer and fewer RV (and boat) manufacturers every year. Many RV companies have reflected the general economy, and 2008 was a turning point for the industry. Many companies (and dealerships) failed and went into bankruptcy.
The large conglomerates, like Berkshire Hathaway, swooped in and bought many brands for 10% or 20% of their original cost and put them together into companies like Forest River. Thor is the same way.
Some of the companies continue to operate separately, while some companies benefit with the economies of scale and they may build 2-3 different brands in one factory. But they all are trying to be everything to every RV owner--a difficult task.
Grand Design has been the only really new company that is competing with The Big Boys' RV companies built out of bankrupt companies. And so far, they appear to be doing great.