I am not a fan of either brand, for the record. But things are not black and white either. Nobody is ignoring the fact, that Intel has the best processor out there, gaming or not. But you seem to ignore the fact, that there are people who are buying AMD processors every day and are absolutely content with their purchases. Just read reviews from web stores. Why are they buying AMD? They have their reasons. The real-world difference between AMD and Intel is not that big, when you actually game, and not reading too much into every benchmark, world wide web has to offer. Choice is good and I am glad AMD is still around to offer that choice, whether you like it or not. AMD has the second-best processor in the world, for significantly less, what's not to like? Nobody is forcing you to buy it, but do not limit options to others, as they may have different things on agenda.
There are people drinking and driving every day too, that doesn't make it a good idea. When it comes to the 8320 vs 3570/4670 you're looking at $80-90, which isn't much when building a gaming machine. Saving $80-90 to get a CPU that's worse at just about everything, while consuming 2x the power, isn't a good way to spend your money no matter how many people are making that mistake.
I'm not giving you a black and white answer. I'm looking at the cost difference and what you're getting for your money. What is your argument? Other people are doing it? Really? What actual reason can you come up with when I counter that argument with "other people are buying Intel too"