This. Also, remember that from the consumer standpoint, PayPal was the first ever trusted payment processor that didn't pass your payment account info (bank, CC#, debit card info) along to the vendor. Granted, they passed along your email+shipping address. But the vendor would have had that info anyhow if you were purchasing some physical item from them.

So there's a large swath of the consumer population that views PayPal positively and will skip a purchase if there's no PayPal option.