An American study has shown that people said they preferred a glass of wine that they were told came from Italy over one that came from India, when they both came from the same bottle. Similarly, they preferred chocolates supposedly from Switzerland over ones from China, when they in fact came from the same supermarket brand. The full story is here. We know that people will knowingly buy counterfeit goods and pretend they are the originals, but this goes much further - people detect differences that don't exist because their preconceptions, or prejudices, tell them one product is better than another.
I wonder how far this applies to beer. Judging by how some people write on the subject, probably quite a lot. We have now moved beyond the realms of the real ale snob: some real ale drinkers blithely dismiss what they call brown beer, meaning I suppose traditional bitters; some condemn many of the products of micro-breweries as being poor quality beers produced by hobbyists rather than serious brewers; some won't have anything to do with the old regional brewers; and some declare that the big brewers are incapable of producing anything worth drinking. I'm oversimplifying for illustrative purposes, but I'm sure you get the general point.
There is some truth in all of these opinions, because the quality of products across brewers will obviously vary; the mistake is to generalise from them. The current buzz word is 'craft', an undefined term imported from the USA, which is really quite meaningless in the British ale context, but is employed to imply a level of discernment: if it's a craft product, it's good, but as far as I can see, we are simply replacing one set of assumptions and generalisations by another. The problem with using undefined terms is that there is nothing to stop anyone from using them. The term 'real ale' was invented and defined precisely by CAMRA and is now accepted to the extent that it's in most modern dictionaries; any brewer who described a beer as real ale when it wasn't could be prosecuted under the Trade Descriptions Act. This is not so with the term 'craft beer', which is often used to describe the new style of keg (which I wrote about in March - here if you're interested), and I can see nothing to stop Tetley's or John Smith's describing their beers thus, even their smoothflows. Certain craft keg fanatics are so evangelical that they condemn CAMRA for not supporting the style, one which is almost certainly undefinable and is excluded by the very name of CAMRA.
To me, all of these people, those who nitpick about real ales and those who advocate craft keg - whatever that is - remind me of those who took part in that wine and chocolate study that I opened this post with. They like to draw lines and say, "This is what I like". We all like boundaries; they make things easier to understand and defining what you do and don't approve of so much simpler. However, if you go too far down that path, like the wine and chocolate people, there is a real chance that what you taste may be influenced by what you see, or what you've read on the pump clip or bottle label.
Most drinkers would probably agree with the statement that you should drink with your taste buds rather than your eyes, but I'm certain from what I've read that many do quite the opposite. Well, that's their loss.