I'm not sure I follow here, the cleaning fee is announced before you confirm the booking isn't it? In a way it's similar to airlines having cheap tickets to then adding seat-choosing fee, bagage fee, etc. The initial low price is slightly deceptive to appear cheaper on aggregators, isn't it?
Here the "scam" is they use same deceptive practice to appear cheaper on the Airbnb map?
For any serious booking, people explore their options and open a few tabs of different listings to pick, since they have to check other things (smoker/non-smoker, pets/no pets, etc). The cleaning fee for the trip is listed there.
Some owners prefer long term stays, so putting a flat higher cleaning fee is a good mechanism to incentivise longer stays imo, as yes, cleaning is time consuming.
Maybe the Map itself could improve to show the total price for the trip instead of base-rate-per-night.