It is not misleading as this is explained in the comments section bellow the chart. Anyway it was just a suggestion for a possible direction to look at.
Maybe not 'misleading' but dubious. I mean, if you want to compare how many threads an OS can handle before it dies vs how many connections it can handle via an event-based system, I think the results are fairly well known at this point. It's not really highlighting anything great about Erlang or Yaws, nor pointing out any particular defect of Apache.