When you have felt a swing where you DO hold the angle you can then identify a swing where you don't. If you've NEVER held the angle you have no idea of the 'feel' so you can't identify it.
The recent experience of PhysEd is IMHO a proof of this point. All of the people you mention:
#1 - Learned as kids
#2 - Represent the tip of a pyramid of people that learned as kids. Given the number of adult amateurs I've seen who learned as kids (like the ones you mention) there is still 90+% of them who have never felt a correct swing.
IMHO it's better to gear your advice to the 90% who didn't and never will without explicit mechanical instruction vs to the <10% that would get it anyway.
There are fairly standard methodologies to teach 'feel' if you don't have it. One of them I've already told you about.
Peter
| 