That is not true. Any type of card can be linked to a paypal account. Be it debit or credit card, paypal accepts linking them as long as the card is operational and compatible with paypal liking process.
Am not certain which country you're from, but payapl has certain restrictions to some countries which can very well cause limitations to the optimal use of paypal accounts to those who belong to paypal restricted countries. I think this is where your problem lies. Am from Nigeria, and in the past, i use to have my MasterCard debit card linked to my PayPal account untill the restriction was put in olace. The card still worked for a while but later got declined as my bank was no longer in operations with paypal services. But still, there's one or two banks over her that their cards are still allowed on paypal account but only for depositing purposes. Anyways, this is the reason why I don't use PayPal that often because the restriction hinders a lot of services.