I know they are good for those looking to own without restrictions or huge debts but I have never heard of anyone buying one to rent out. I would check your area and see if there are others doing this.
It depends on where you live. I don't know of a single one anywhere in my area so it wouldn't be a good idea to invest in something like this. I do know of someone who has somewhat of a tiny house on their property but it is more of an office. It is a room with a small kitchen area and bathroom.
Given the economy and how a lot of millennials can't afford to buy homes, I would say now is a good time to jump on the trend. It is just a matter of finding them to buy or getting them built yourself. I know some areas would allow several tiny homes on one property and it would function like a trailer park.
Most people looking to rent a place like this will know what they are looking for. What size is the home? $35,000 really isn't all that much for a modern tiny home. I have seen many that have been well over $70,000.