All this ambiguous, eroded (by time), inaccurate, obfuscated, partially true, partially false, wholly off-base nonsense.
1. It's a question of degree. All traditional residential appraisal reports based on the SCA are fundamentally flawed, subject to subjective judgement of unmeasured features such as condition, quality, view, functional utility and wholly unconstrained by underlying mathematical relationships. Having said that, some appraiser's subjective judgements are better (founded by experience and logic) than others, - but that's an issue that is hard to monitor and control when dealing with trainees. You have to minimize the impact of subjective valuation in appraisal - a doable task that TAF, the AI and other appraisal organizations have never even tried to undertake, because they lack the intellectual capacity and also resist hiring mathematicians and other scientists and competent analysts, along with legal experts, to do the necessary work on their behalf.
2. An appraiser supervisor can do a reasonable job of overseeing and reviewing appraisal reports, in the vast majority of cases, by studying decent quality photographs from field appraiser trainees. - So that immediate supervision of reasonably intelligent appraiser trainees is simply an expensive luxury - that can be done away with. Apparently, it was a requirement set up through some kind of compromise in order to reduce an influx of appraisers (but it had the opposite effect - giving appraisers willing to skirt the regulations a HUGE advantage).
2a. One might conclude from #2 that unnecessary regulations are an advantage for a select group of established appraisers who have the wherewithal (e.g. connections or infrastructure knowledge) to avoid profit diminishing restrictions provided by said regulations). But of course time changes everything. Said "established appraisers" may eventually fall out of favor with their connections, or their connections fall out of favor higher up the chain or simply disappear for one reason or another.
The whole appraisal system was highly flawed to begin with. And it still is. It does get the job done with minimal short-term cost - but the long-term cost is on the order of hundreds of billions of dollars, if not trillions.