My wife's sister and brother-in-law bought a trailer house after graduating from college. Their rationale went like this - A) It would be way cheaper than buying a house, B) they had no kids and didn't need much room, and C) they planned on moving from Charlottesville, VA where my BIL's first job was, to Lynchburg VA within 5 years, so they would just be able to move the trailer when they moved and avoid having to sell a house.
They were reasonably happy with the trailer, and eventually moved it to live closer to my in-laws. The problem came when they decided to sell the trailer and buy a home after living in it for about 8 years. The trailer that they had paid just under $60K for would sell for less than $35K. Basically they were able to sell it for just enough to pay what they still owed on the loan - and they were probably lucky. I would imagine some of these "tiny house" people will find themselves in the same boat....errrrr -trailer.