Michael "Savage" Weiner is indeed an herbalist who has written at least one book on the subject. He worked at the office of a physician I went to for awhile in Sausalito. The doctor is well thought of, and Weiner was too at the time..circa 1985. But I didn't like Weiner, found him too egotistical to be a good practitioner, and only saw him one time.
I have no idea when he became Savage, in both the upper- and lower-case sense. Perhaps it is his natural reaction to the liberal idiocy in the San Fran area, which has become so extreme in recent years. Extreme circumstances may require extreme shouting.
Two reasons: 1. To quiet down vehement criticism and bad publicity that had its genesis when a caller to KGO's Bernie Ward ("The Lion of the Left") snuck a reference to then-Mayor Willie Brown as a "jungle bunny," ABC/Disney required all employees to go through "sensitivity training." Savage, who was a substitute host at KGO at the time, rebelled.
You can't be a talk show host with the last name "Weiner," regardless of how you pronounce it.