You're right about the hosts, a lot of them are not interested.

But I still find people on LeBonCoin who are. They like to fill their appartment/home and not bother for a month, it's convenient. I might clarify that I find them not in big cities though. That might be the point: hosts in smaller cities are interested. And like you said, there are also people who rent on holidays and not the rest of the year. Plus, it's cheaper since they usually don't have anyone.