It depends on the bar/pub, IME. I haven't drunk in 17 years, but am more than happy to join friends on a night out, and drink whatever interesting-looking soft drinks the pub has available. Only on a handful of occasions has some eejit made an issue of it.

I live in a region where tipping is near zero in bars, so that's not an issue. And as for the owners, well, I'm sure they're happy with the MASSIVE markup on the drinks they serve me.