Saying you're not perfect is no defense against criticism.
It is when your argument is that it claims to or should be perfect:
There have been dozens of different attempts at categorizing personality. I prefer the Myers-Briggs typology. Of course with the handful of concrete knowledge we have on human thought and personality, none of them are going to be as accurate as you might like. That being said, I think the "Temperaments" setup is a bit too... unrefined. Its just taking a few broad categories and saying they exist and how they can be combined to explain each other. It doesn't really use any true scientific reasoning. Just a kind of, "Hey have you guys noticed" approach that has evolved over hundreds of years. That's not to say that broad observation isn't a useful tool in evolving a theory.
Your argument was that it wasn't perfect. My response was that of course it isn't; otherwise there would be millions or possibly billions of different temperaments, since everyone has a unique personality. The reason I thought you hadn't read the article is because it says it very clearly in the introduction and "general misconceptions" section.
I'm sorry if I sound angry or rude, but I've seen similar criticisms against the temperaments that the article tries to address, and I just wanted to clear that up, since so many people seem to instantly dismiss them.
Honestly, I feel like the best way to understand the temperaments (or any horoscope-type thing) is to see how it applies to real life. Seeing what you'd read, I'd encourage you to try and recognize it in people you know, or in media characters. (Set, for example, is Phlegmatic/Melancholic -- very submissive, peaceful, kind, and meek. If you read the Phlegmatic/Melancholic blurb I think you'll see that it fits. And Rahel, for example, seems to be Choleric/Melancholic -- dominant, stubborn, hard to get along with, analytical, and rational)
It's all your decision in the end, though, so if you really think that the temperaments are hogwash, then whatever, I won't try to convince you. I'm not very good at that anyway.