1. high transaction fees. As many exchange sites charge high fees on PayPal transactions.
2. If the platform does not accept IDR, currency conversion fees apply. PayPal fees are 3.5% above exchange rate. For all other currencies, the fee is 4% above the exchange rate.
Users doesn't need to pay any transaction fee, and that is a big positive with Bitcoins in PayPal platform. But obviously, the merchants needs to pay the fee, just like any other payment option in PayPal (I guess it is around 1.8% to 2%, depending on the geography). And secondly, their services are limited to American users right now. Once they expand their operations to global users, you may be able to directly pay with IDR.