I don't know if a lot of hosts are using hospitable or etc to automate the system, but I'm not sure I would want to leave every guest a review. That seems like a sure fire way to backfire for me.
As is, I do get a lot of guests that leave me 5 star reviews, and also some that would leave me a 4* review since they don't know how the review system works or the stay was less than perfect.
The thing is though, I no longer want to educate guests on the airbnb review system since it could be considered as review fishing.
Another thing is, I guess hosts that VET their guests using the 'accept/deny reservation' process can possibly afford to review almost every single guest, since they can somewhat control what guests they are getting. For my listings with instant booking turned on, there is no way to control that. UNLESS they have instant booking turned on, and accept every single guest, then I could not take their opinion at face value and do the same thing they're doing since fundamentally it's not the same at all.