What're the issues with PayPal that you're aware of?
I am just a user, not a merchant so I am not sure what the issues would be from that side of the transactions, I personally avoid keeping too much money in PayPal just in case they somehow block my account for some bullshit reason.
Edit: I would prefer not to go off topic, unless is related with why some big companies refuse to use PayPal and others do use it. As an example I could not buy audio books from amazon so my money went to a different company that accepted PayPal.
Also, maintaining each payment gateway has an implementation and maintenance cost. Add it all up, and assuming that the number of potential customers like you that only have paypal is small, and it's easy to see why companies may choose not to implement it.
I don't know the details of any of these places, I was just giving a reason why a company may not implement a particular payment processor. It's based on a balance of factors, not just a simple "support X get more paying customers."