PayPal is the only payment service that doesn't require me to write any code, or to maintain a server that can run server-side code. It also doesn't require me to store any customer information on a server. I download a transaction history in PDF format every year for my taxes, and I delete the customer information, just leaving the dollar amounts. I don't want your steenkin personal info. Hack away, there's nothing to steal. ;-)
Oddly enough, I'm a pretty good programmer and I love to write code, but also as a lone wolf, I think maintaining a secure website against adversaries who are smarter than me, is over my head. And it's not my business. I kinda started this business as an escape from code.
There are a few customers who really really don't like PP, so I have to offer an "out" and for my little business, they're OK with sending a money order. Oddly enough there is a strong correlation between those customers, and customers who want to talk with me on the phone. There will always be a few people who just have not gotten into the whole computer thing.
It is quite possible that I'm lucky to be in a little market niche where nothing ever goes wrong with orders. My product is a tangible physical deliverable. I am quick to refund if someone is unhappy.