I assume they don't have to set up a dedicated payment processors if their existing ones support PayPal already? I get the impression that merchants don't really have a choice whether the user will pay with Bitcoin or not. It's more like the decision lies with the user themselves. I see some new threads asking which payment processors are good for Bitcoin with low fees/privacy-friendly, etc, regularly in this forum, btw, so I think some of them do care about privacy too.