Please don't crucify me. Some hours ago PayPal payment system made some good decision of incorporating into their system buy and sell of Bitcoin, this has made it price to move from it former state. Basically ripple would have be the best for them IMO, seeing that ripple is the future of cryptocurrency irrespective of it centralization. As a ripple holder from inception, I did want Paypal to reconsider the use of ripple as it stand at the frontier of this era of digital currency. Hope this message get to PayPal team for appropriate actions.
Quite simply, whether you know it or not, ripple is nowhere near as popular as bitcoin. It has never entered the mainstream public media (although it might get reported on sporadically) but lots of people have heard of bitcoin. You should be happy that bitcoin has been accepted by paypal, as it gives more people exposure to the idea of cryptocurrency and makes it much more likely that paypal will allow trading of other ones in future.
Bitcoin is even being referred to as when the topic is cryptocurrency. Many people still are thinking that Bitcoin is a general term for cryptos because of its popularity which I think is not a surprise to knke that it is always included on any actions regarding acceptance of cryptos. But I agree, there's no need to feel upset if your preferred crypto is not on the list to be accepted in such network, because there will be further developments with regards to this, and if this would be benefitting them, more coins will be included for sure. To put it simpler, popularity is their main domain on choosing the cryptos they would include in their network.