@Pat280 I'm not missing the point. Nor did I ever say "I'm a host, you just don't understand". I did try to explain it to you way back when you first started this thread.
How could I justify someone else's cleaning charge? Neither I nor you know how much time and expense was actually incurred in the clean-up after your party. It could easily have taken 2 people an entire day to clean it up to the standard that it would be ready for the next guests. Nor do either of us know the cost of the cleaning products used, whether the host had to hire a truck to haul away all the bags of garbage produced, or load it up in their own vehicle, take it to the dump and pay a tipping fee.
Perhaps the host was seriously overcharging for the cleaning. Again, neither you or I have any way of knowing that and hosts are not required to "justify" their charges, as you, as a guest can either take it or leave it.
Most people, when making a significant purchase, unless they are wealthy and money is no object, do comparison shopping, whether it's an airline ticket, an appliance, a power tool, a piece of furniture. They do the research, look at the price, the terms and conditions, and make a decision as to where and what to buy. You don't find an airline ticket cheaper on one site than another, and then go back to the more expensive site and demand that they "justify" what they are charging.
It's no different with an Airbnb- you don't like the price and the terms, you just move on to book somewhere else.