In the future, hosts will be able to make their own "products" which will be free of charge - like a nearby hike or beach that they recommend. I think free activities mixed in with paid tours, combined with a host's custom recommendations per (paid) activity (which is currently implemented), should make an honest, wholesome and reliable guide.

Also keep in mind that it won't always be just touristy tours. Along the lines of crazypyro's comment, we'll be adding other services like transportation and restaurant reservations.