I think it is because bicycle tourists by in large are good folks. Appearances can be deceiving. I had a guest a gentleman in his 70s. I rode out to meet him. It looked like he was hauling his whole house on a trailer. Complete with full sized lantern and 2 large bottles of orange soda pop. His first statement to me was "your hills sure are steep"! We smiled and he didn't have a tooth in this mouth. I thought great I am hosting a homeless guy!

That night be bought me dinner. Turns out he lost his teeth on his transam. He was just starting, it was a pouring rain, he was on a bike trail. His vision was very limited because of the rain. He slammed right into a sofa that someone had thrown out, crashed and lost all of his teeth yet decided to continue his trip anyway after being checked out by a doctor. He was a heck of a nice uy.

I did have one guy I suspected was homeless but using warmshowers as a place to stay. He came from a previous host not even 20 miles away. I ended up calling the host ans he suspected the same thing.

For the most part my experiences have been positive as both host and guest. I have had people stay with me from all over the world. Including one guest from China. Most of my guest seem to come from South Korea for some reason. I have had 3. One of them was a monk. Koreans must really love the US.

I have also stayed at a few warmshowers ./ couch surfing hosts in Italy. That is a lot of fun. You get to see how people live and you find out not much different than you except they speak a different language.