Im the joint tenant of a pub in Oxford, and I will say that as long as you have a half decent location, it is entirely in your hands if you sink or swim. There are some god awful pubs out there, awful beer, crap uninterested barmen etc. It is up to the pubs to be a good place to be. I would also say that in many areas there are perhaps to many pubs to be viable, something has to give.
One last point - many people would'nt know a good pub if it kicked them in the nuts, hence awful town centre pubs are always busy.