I think you might confuse morals ( what people should do, be better) with ethics - USPAP has a set of ethical standards, not moral standards. Same for other professions. The problem is that appraisers are often punished for acting like appraisers - fulfilling a neutral umpire role /
The fact that the AMC firewall is a fail, with just as much or more pressure to "make value" than in the bad old days is a travesty. An argument that if it made things even 10% better is worth it is ridiculous. Appraisers who fear work being cut off if they come in "low" on more than rare occasion cn not function in their intended role. Many try the best they can within that capacity, others have given up and just want to collect a fee, others simply will not accept mortgage lending work because of this conflict of interest. Teh same might apply to commercial but there is a much wider client pool and type of work available, making it easier to say " no"
Having AMCs engage in the demoralizing practice of fee bidding to "win" an assignment contributed to the appraisers' lack of confidence in standing up to these all-powerful clients who control a large portion of work. RE agents and lenders do not have this problem—their potential customers are thousands and even hundreds of thousands of consumers and buyers.
There are some clients who are more ethical wrt dropping appraisers for not hitting value and most of them are not operating in the AMC order pieple tohgh to be fair some direct order lenders or lenders who own a captive order AMC can be no better.