Paypal's charge-back is actually invented to protect the buyers from possible scams. But buyers now a days misusing it to gain free usage of products by claiming refund within 41 days. But bitcoin is protected against charge-backs so all the transactions are final.
That is only true when you don't run an official business that is forced by law to refund buyers when they, let's say, don't want their product anymore within 14 days. Though bitcoin has the advantage that it is harder to get scammed. With chargebacks of course. It's actually pretty much easier to scam someone the normal way because no chargeback exists.