Fuji,
I did raise an eyebrow about your original assertion, but Scooter Boy has clearly never enjoyed the Yak-18T, which whilst lacking de-ice and, arguably, a second engine, is an admirable example of an aerobatic IFR tourer.
Whether this material inaccuracy brings into doubt the rest of his argument, I don't know.
Plenty of ATPLs down my way who also indulge in the aerobatic 'dark side' - including one, I kid you not, who had to command a fresh 250 hour First Officer on a 737 to put his feet on the rudder pedals when flying the aircraft, said FO insisting he'd been trained not to. Presumably he thought George would help him out with the pedal work.