Indirectly, yes, I think that was a problem - by buying PayPal and closing their own payment service ("BillPoint"?) they ensured PayPal never had to worry about competition again.
and not to mention completely blocking Google Payments from having any part in ebay auctions, and shutting down the excellent Western Union Auction Payments service, where the buyer pays the fee to send the payment, and ebay can't double dip in the fees (charging the seller a fee for the final value and then charging the seller a fee to receive payment through paypal).