Not strictly true.
Paypal is biased 100% towards the buyer.
And if you accept cards, you can choose to accept debit cards, and not credit. My buddy runs a software business, he doesn't accept credit cards at all, all his business is conducted by debit card, direct transfer (BACS) check or cash, and he's had no issues.
Also with credit card merchants, you can choose a company that suits you. Cardsave is brilliant - chargebacks are very rare, and it's biased equally between buyer and seller. My sister has used them for 3 years with no issues.
Paypal is just plain rubbish - have you ever tried calling their well-hidden number, and spoken to a REAL human? I had it on mt site, but have since removed it as a payment gateway. At least, if a credit card transaction is subject to a charge back, you can call and actually speak to a HUMAN.