As others have suggested, I believe this is a clear sign that ebay is exerting monopolistic power. Let me get out my sharp pencil...
ebay is drastically reducing payment options for its customers, many of whom loath using Paypal. Many, many ebay customers, although not all, will convert to using PayPal because other selling options are less attractive (again, not all customers will switch). In the process, ebay will reap greater Paypal profits, regardless of the reason for the elimination of currently used payment options.
How is this not monopolistic?
ebay states, "We are going to take learnings from it and apply them accordingly." Only a moron would believe that customer response would be anything but negative. Thus, ebay simply wants to know how much auction profits will fall off versus Paypal profit increase. Given that information, ebay can do some simple calculations about gross potential profit increase or decrease. With that information, ebay can roll this policy into other countries. By the way, a good test market for this would be a country that has a lower percentage of Paypal users, as is the case in Australia.
For what it's worth, Microsoft recently admitted to doing worse. Those using Vista are presented with a plethora of security warnings, all of which require some sort of confirmation, and many of which require entering of a password. Vista users have been annoyed by this.
Recently, at a conference Microsoft stated that the reason for this feature is intentionally to annoy users. Their stated logic is that by annoying the users, software developers would be encouraged to write software that requires fewer of these security warnings/confirmations. The truly galling aspect of this is that Microsoft gladly stated this at a conference and not as part of court proceedings. In other words Microsoft publicly states that annoying users is a feature of their software.
How is this not a display of monopolistic powers?
I read this, including statements from Microsoft, in an article in OSNews (osnews.com). If anyone wants the article and can't find it, I'll look it up.