But a punter cancelling on an SP is essentially money lost for the SP. A punter who suffers a cancel will have his time/opportunity to punt wasted, but keeps his cash. In my opinion, the effect of time wastage is not the same for both parties
So maybe time wasting is not the right name to describe it.
There is no money lost only opportunity. She hasn't earned that money by taking a booking, she hasn't delivered any service.
There are no signed contracts on incontravertible terms. All arrangements are subject to availability, honesty of offer and change of circumstance on either party's behalf.
You'll be arguing that walking into a shop commits a browser to making a purchase next. Shoppers can pick things up then change their mind without prejudice up to the moment of purchase provided they have not deliberately damaged or (part) consumed the product prematurely.
Where's the compensation if she's shit at delivering her service, why should her earnings be considered assured when nothing about her offering is guaranteed?
Why does a punter cancel or no show?
1) He's an a-hole timewaster with no intent to go in the first place.
2) He's nervous and easily dissuaded by his own internal dialog
3) He's put off by something the SP does or doesn't do to instill confidence in the booking.
4) Something comes up to prevent him turning up
5) The SP proves to be not as expected or promised wrt looks, age, attitude, nationality, ethnicity, etc. Timely posting of reviews with current details about an SP can prevent ill-founded interest and booking or hasty cancellation.
In all but 1) if he notifies the SP before the time of the meeting (the sooner the better) then he has done his part in acting in good faith and consideration.