Because none of the current toy haulers are made to handle a 5,000lb Jeep and a 900lb bike. Most toy haulers only have a 3-4,000 payload. They are made for SXS's, quads, motorcycles, golf carts and such. The other issue I have is getting in and out of the Jeep in a enclosed trailer. I'm not quite as nimble as I use to be so having the open deck works better. Also having the dirty Jeep inside isn't my idea of smart. I'd rather be able to pull into a self wash place and pressure wash the Jeep right there on the trailer.
The only company that makes a toy hauler that could handle the Jeep and bike is Dune Sport.