Hmm…Frank Gambale seems to have broken down the mechanics of his picking. But he’s Frank Gambale, right? He’s not Eric Johnson, either.
The players you mention - Bonamassa and Gales - are advanced players, so they should be excluded as examples, for obvious reasons.
I largely agree with this following point of your rejoinder:
…with the possible exception of Frank Gambale.
On the other hand, every guitarist is capable, or should be capable, of “showing their riffs” to other players, especially advanced players. This refers to the left hand.
Although EJ can’t explain his picking, which with most players, until Troy Grady, is intuitive anyway, he should be quite capable of explaining the riffs he does in more detail, or at least his chord work. As it stands, his instruction is very general.
We aren’t supposed to speculate on his motives.