While I personally loath Paypal I still have an account.
While I know nothing about the EnWorld situation specifically the fact is that the credit card system is not really set up to handle micropayments.
Especially outside of the US credit card companies seem to have basically given up on the lower size transaction market. In Japan a lot of credit cards now come imbedded with chips for different small-size payment systems (Edy, etc).
Merchants in Singapore just charge you extra if you want to use a credit card and refuse small transactions completely. Taxi drivers will, literally, have a screaming fit if you try to use one (often in a cab where there are adds offering you “free prizes” if you “pay for this ride with your Mastercard”).
The US is, from my admittedly limited experience, abnormal in the degree of credit card penetration.