When Ebay first started requiring Paypal, it made sense - Paypal was clearly the frontrunner for online payments and Ebay's homegrown effort was a pale comparison. Also Ebay was a real powerhouse that could move the needle with a decision like that.
Today I feel like Paypal has a lot more traction than Ebay, and this is going to be a big flop for them. As a consumer I don't want to sign up for yet another payment service.