I'm another person who teaches at a tesp prep place. The first time I took the GRE (many years ago, without reading anything about the test beforehand), I got a 3 on the AWA section as well. I wrote a wonderfully detailed, cohesive and slightly sarcastic essay. Unfortunately, that's not what they were looking for. Once I was more familiar with the test, I took it again in preparation for the application process. The second time I received a 5.5 for a stiff, uninspired, cardboard sham of an essay.
As everyone else is explaining, the GRE AWA section is just another hoop to jump through during the application process. Imagine how great we're all going to be at acrobatics by the time this is done!