No one likes people who take advantage of people when they are hurting.
Self-aggrandizing sales pitches seem to fall in that category.
If someone had a 65% cure (or a car that REALLY runs on water alone)---you
wouldn't have to sell it.
Robert Ringer (noted author of the 70s/80s) coined a term I liked:
SHMEXPERTS
(I'm no expert but I suspect he was trying to combine 'schmuck' & 'expert')