One of my hosts did the same. She was more casual about it.
But I also heard from people how they hated when guests would show up and start acting like it was for dating. So many profiles would explicitly state that they were not looking for dates.
I think hosts learned to post very clearly if they were not looking for dates. That way potential guests would not misunderstand acceptance (for a place to stay) as also being a potential for romance. I saw plenty of host profiles that were very clear on their disinterest in romance. I did not see any profiles that said "looking for dates", as I'm sure that would not have worked out well... imagine the emailed photos they would receive...
But in her case, she was super alpha female (gay), and I _think_ she had an eye for people who would be receptive to that. But she was also very cool, so I'm sure if she didn't get the right vibe she wouldn't push something that would become awkward.
From my background, I wouldn't have advised single women to host men. But two of the people who hosted me were single women, so I guess they were just more comfortable (or perhaps Swiss people are less accustomed to bad behaviors?
But I also heard from people how they hated when guests would show up and start acting like it was for dating. So many profiles would explicitly state that they were not looking for dates.