Slight exaggeration and sweeping generalization
It depends on how you define crooks. I've seen downright criminal behavior to just simple exaggerated marketing tactics.
I did use the word "mostly" in there so it's not a sweeping generalization. In such a tight margin business with so much competition it seems those who attempt to do things honestly end up degenerating into crooks or go out of business. Also why savvy aircraft owners often start their own management business or buy a certificate.