Well, he does suggest, at the end, that there are probably better representations.
I would rather the author go into a bit of a discussion about what the data represents and what different ways this could be presented. I can't help to get the feeling that the choice of a scatter plot is more or less arbitrary.
If you Google search for "apache bench gnuplot", you'll find a very similar gnuplot template that has been circulated for a very long time, but everyone seems to think that the resulting plot is response time over time.
I'm definitely going to follow up on the issue. I'm a mediocre programmer, so gnuplot is pretty hard for me, but I keep having these "ah ha" moments. My next post will look at each graph in more detail and try to explain just what is being shown in each.