Especially if they never met you, they may just be thinking "transactionally." Eg "They said they would refund if they could and they did. Done."
Versus a guest you've been interacting with who is actually staying has developed much more of a rapport with you. If you additionally offered something of yours as a solution, you've cultivated much more of a relationship with them. So they are likely to respond much more "humanly" and with appreciation for you, as a person. That's what a homeshare is.
But when they've just done the reservation/cancellation online, you are still more like a hotel from their perspective, even though for you, it's still your home you're sharing. It's just a matter of perspective.