It is obvious that you have an irrational bias against social dancers. The basis of your hostility seems to be that they are unintersted in competitive dance. So what?
What level of Amateur Medal do you consider 'high grade' BTW?
As far as my teaching methods are concerned, I happen to have started a class combining Foxtrot & Samba just last week. The pupils are 'Improvers' who have been dancing for 18 weeks, but not, so far, in these styles.
We covered the Samba bounce action in the first class, and I had them dancing Whisks to L & R (with quite convincing Latin Cross positions on Step 2), and making the bounce action without any obvious effort. We also started the Foxtrot with a Feather into Reverse Turn, and spent several minutes considering the effect of the side-leading and the CBMP OP position of the man on the last step of the Feather, and its importance in the swing into Step 1 of the Reverse Turn. Of course we looked at the division of the turn, and the need to avoid over-rotation on the second turning step, so that the couple can move directly down LOD, without having pulled the lady off balance on her heel turn (and we found time to have the ladies dancing a reasonable heel turn too).