Light beer (beer that is reduced in alcohol content) is LOW in purine indeed. And what everyone else is telling you—beer could increase your risk for gout and recurring attacks—is also true. I'm not contradicting myself because:
It's the alcohol in the beer that plays an important role in increasing your risk for gout.
Alcohol could be converted to lactic acid, which will be excreted by the kidneys. If you drink much alcohol, your kidneys will work hard to get rid of the lactic acid. However, uric acid, the breakdown product of purine, is supposed to be excreted by the kidneys as well. If your kidneys are working hard to get rid of much more lactic acid than usual, less uric acid could be passed. As a result, there's a build-up of uric acid in your body, which means a higher risk for gout.