bathrooms tend to be damp if there is not a proper ventillation system in place, and this seems to be fighting against it. it could be an added benefit for some places, but don't think it is the most elegant solution for everyone.
to get dry, 40+ degree air, i just need to open the window during the summer in the city i'm from! but you might still value it for clothes that can't be dried against direct sunlight.
Good ventilation is a must for Japanese homes because it's going to be a mold haven without it. Modern Japanese bathrooms in particular are designed to dry quickly. The bathroom ventilation system runs around the clock and they even have floors that drain the water and prevent puddles from staying forever.
to get dry, 40+ degree air, i just need to open the window during the summer in the city i'm from! but you might still value it for clothes that can't be dried against direct sunlight.