This is a good point. Depending on the stage of the company and the type of people working there it is very possible to have productive working relationships that would never extend to events outside the office.
But that doesn't mean a first meeting outside the office over beer or coffee isn't a good idea. It isn't necessarily part of "bro culture" either.
I've found that it's a good way to have a conversation with someone to get a feel for what they like to think about, and hopefully learn a little bit about what kind of decision maker someone is.
