This behavior is *not* restricted to pool, though some may like to showcase pool as the black sheep in the family, so to speak.
Look at the low-life loan companies preying on innocent people with bad credit or no credit who need money to save their homes. They bait them in, paying huge up-front fees, and then do nothing to help them. Some end up losing their home to these loan grifters.
Some credit card companies do the same thing, enticing new customers and then slamming them with extra charges after the fact, making tens of millions of dollars while their customers literally go broke. There's no laws ruling the credit card companies -- and now the banks. They can pad on fees and extra charges willy-nilly in order to make a profit.
Insurance companies, especially medical insurance companies, are doing the same thing, trying to trick the public with their foolery. They raise the premiums every year 25, 30, 35, and 40 percent, and there ain't nothing the citizenry can do about it.
No, this is not restricted to pool. In fact, pool is mild compared to some of these above-referenced entities who got rich while their unsuspecting customers suffered.