Yeah, right: So Hermie trolls up to his instructor and says ' I can't fathom your final approach advice so I've asked a load of people on the internet who I don't know, have never met and have indeterminate credentials and they all say you're cr ap'.
No, Hermie simply says politely that he'd like to try a different instructor for a bit. If pushed, he could say he's finding things hard and thinks it might help. But actually, he doesn't NEED to give a reason; it's his money and his choice. Any problem, go to a different flying school!
Whirly (who did just that after about 30 hours on helicopters, refused to criticise or discuss it in detail, but said she either wanted a new instructor or a new school...and got a new instructor!)