Boo hoo more victimhood, having to sit thorugh a boring class - a govt license which is what an appraisal license is comes with a bit of obligaoin in exzhnge for the advantages - abba hoode hit
USPAP is a standard of professional ethics by which at least a benchmark measurement can be made.
It is not about an appraiser being personally ethical - it is about in their profession, can be practice to the ethical standard. An appraiser can cheat on their spouse and be a sleaze in private, but if they follow professional ethics, then they fulfill the requirement for appraisals. The reverse is true - an appraiser can be a great family person and upstanding citizen, but if they mislead, conspire to commit fraud, or violate any of the ethical standards of USPAP they can face the consequences in their appraisal career.
It cant force people but it can act as a deterrent and a means of punishment for those that violate.