Generally crypto currency exchanges do not support PayPal or Credit Cards or any other payment method that is reversible, because the risk is detrimental to their business model. Simply because by design all BitCoin transactions are irreversible and there is no way for them to get their money back.
If you do find an Exchange that supports these payment methods it is likely that they will have significantly higher transaction fees.
Well , the main reasons is that there are lots of scammers that take advantage of those company policies.
If there weren't people who only thought about those schemes there won't be any problem.
