I hit it because my wife had a paypal account before I did, and we share a joint account. It's really irritating, but I found a work-around (use another account) and moved on.
Presumably it keeps people from just spam-creating new accounts every time they get banned.
In this case, however, it's hurting their business by being too strict. They could, for example, let you have at most two accounts linked to solve the problem some married people have.
If that were the case, then they should be able to tell when you try to link your bank account to a second PayPal account that the first one was banned. Slap those people in the face... not everyone. As long as all PayPal accounts linked to a bank account are in good standing, why limit it to just two?
I do not see why they need to stop spam creation of accounts. They can just ban the bank account in addition to the Paypal account. Without any bank account or credit card connected to the Paypal account it is not very harmful to Paypal.
Someone might be able to use the dozens of accounts for fraud before they could catch them and put a stop to it. If the money is already gone, Paypal would suffer the losses.
The way I operate my business and personal bank and PayPal accounts means I have to shuffle money around to work with this rule. Why, PayPal?