Why was Payment Protection Insurance sold?

Payment Protection Insurance (PPI) according to many leading financial experts is a scam, it’s been mis-sold, mis-placed and mis-trusted - but why did the banks, lenders and providers sell it in the first place? This could be the answer: When you took out a PPI policy with a borrowing, be it a mortgage, credit card or loan; the sales person typically received 50 to 80% commission based on your initial premium. So you can imagine they were eager to convince you that you needed it! According to...