Not 100% true.
You can still chargeback through your credit card. But you can't do the chargeback through PayPal's means.
This means that, if somebody steals a PayPal account and sends you money for something, the real owner of the account can claim that their account was stolen, file the chargeback through their credit card provider, and PayPal will take the money back.
This means that using NON-VERIFIED accounts with personal gifts is the SAFEST way, as this means that there isn't a credit card attached to the PayPal account, so there's no way it can be charged back (that I'm aware of).