Remember, this all started because a Warbird company selling bucket-list rides in warbirds, which aren’t certificated aircraft, did so by calling it “flight instruction”. THEIR lawyers took a scorched-earth approach trying to justify it in a way which dragged a number of other legitimate training activities into the discussion/decision, from what I understand.
People can gripe about too much gubmint, too many laws, etc. all they want. The reality is, most laws come into existence because someone somewhere pushed the envelope on reasonableness so hard that a law ended up being the way to enforce common sense, IMHO - not because someone somewhere got bored and decided to write a law. Just my non-lawyer, non-politician opinion.
I know exactly how this came up. My question is intended to cut away all that extraneous crap and get to the heart of the issue. What purpose does the rule serve? It might serve a purpose that is not obvious because the regulations are complex and are interwoven.