That was one of the theories that people looking for a "profit motive" saw from Day One. The guy who did that chart, Dr. Horowitz, evidently felt that, since he was looking to make a buck off of the anthrax attacks, the culprit must have had the same motive.
I have no reason to believe that anyone other the Dr. Bruce Ivins was involved.
Too bad. You said: "...this web site was created to analyze the data related to the anthrax attacks when the culprit was not yet known. Now that the culprit has been presumably correctly identified, what should I be analyzing?"
If you were originally on the right track, you let yourself get switched off by the FBI.