Beecher is saying that anyone who says that simple spore preparations are not particularly dangerous is misguiding research and preparedness efforts for bioweapons attacks. It is a stupid and dangerous thing to say or even imply.
You can argue that he shouldn't have mentioned the attack anthrax, but the article was about the "Forensic Application of Microbiological Cultural Analysis to Identify Mail Intentionally Contaminated with Bacillus anthracis spores." It's all about how the anthrax contaminated mail bags in 2001 were examined and all the precautions used, etc. It is about how cross contamination occurred and how you cannot really put anthrax into an envelope without heavily contaminating the outer surface of the envelope. The purpose of the article is to provide original research and inside information about the work done in this area after the anthrax attacks of 2001.
To say that they shouldn't have provided this information unless they also answered all the conspiracy theory questions about coated spores is just plain STUPID. It's STUPID if you say it, and it's STUPID if the editor of the magazine says it.
In reality, the whole argument is about the fact that Beecher said that people who worked directly with the attack anthrax say it was "comprised simply of spores purified to different extents." And there are conspiracy theorists who believe otherwise -- totally basing their beliefs on a comment in a newsletter published by AFIP which said that "silica" was DETECTED in the spores by a device that can detect UNSEEN elements.
Since the "silica" believed or imagined to the present could not be seen, the powder was "comprised simply of spores purified to different extents." There should be no dispute.
But clearly conspiracy theorists will find fault in anything that does not directly address their beliefs, and they'll find fault in anything that disproves their beliefs.