I've participated in couch surfing for years when I was younger (single/childless) & the worst that happened (I hosted a lot more than I surfed) was that some people are just not that nice/interesting. I had many more positive experiences.

Keep in mind I'm a pretty big, able-bodied guy & at the time I was in my 20s. If I was a small woman living alone I may have skipped hosting single men.