The internet has made it easy for people to do research and be more educated about things, and I think that's a good thing. I think we're losing our culture when you drive around cities and they all look the same, with the same chains restaurants, the same stores in the same old strip malls.
So, IMO, there's a good side to being demanding. It's awesome if people seek out restaurants that are local and not part of a chain, and demanding food or service that's better than average.
But, there's no excuse to be rude. It's a fine line. I wasn't there, so I can't comment on the original story. Ultimately, I just think it's okay to be a little snobby, but not to be rude or disrespectful.