Why do so few of the experts at "physics911" have advanced degrees in engineering or physics?

Because you do not even need a science degree to perform some of the tasks involved in studying the "physics of 911." You need web designers and account and other miscellaneous staff. You need non-PhD's to handle the computing and development the equipment/techniques for data acquisition. Also, a degree is just a piece of paper. It does not limit you to a particular field. Someone who studies biology can turn and study Physics.