Wow @Carol35
Although I don't think the original suggestion is feasible I think your comment is harsh. I would love BNB to team up with charities that provide a space for young homeless people.
I do actual share my home with young homeless people through a local scheme, which offers young vetted homeless people who would otherwise be on the streets with a safe place and meal for the night with vetted hosts.
This scheme operates in a number of cities in the UK. https://uk.depaulcharity.org/NightstopUK
Without exception all the young people I have hosted have been lovely, grateful and on the streets through no fault of their own - domestic violence, mental illness within the family etc.