Only one restaurant I go to takes it, the one that has little terminals at each table. I'm not sure how the mechanics will play out for restaurant payment. Personally I don't like the table terminal, but maybe someone will come up with a bill carrier that can take payment.
That being said I use it at trader joes and sprouts, and when Starbucks finishes rolling out Apple Pay I'll use it there too.
It's just very convenient and fast. It makes chip and pin cards seem like five steps backwards.
But why would they. It's a lot of trouble, and being a bank gives you the right to lend in money from the public.
It's still possible to provide payment services without being a bank.
I think they could more or less buy VISA and pay in cash, and that makes more sense if you want to make money on retail payments.