Like a lot of hunters, he thinks the Second Amendment is about hunting. It's not.
Even in his "apology", he demonstrated that he still doesn't understand that basic fact.
Plus, there is no viable or reasonable distinction between so-called "assault weapons" (which aren't assault weapons at all - an assault weapon is a small-caliber, select fire lightweight rifle for use by paratroopers/special forces) and "ordinary" rifles. The distinctions as drawn in the law are cosmetic only.
So the real problem is that this man, despite his long career on the hunting side, has demonstrated that he still doesn't get it.
Zumbo forgot who supported him and how it is all connected together in trying to protect gun rights. His log cabin near Yellowstone and long tenure with the Outdoorsman trade amount to an Ivory tower. He was lucky but forgot who he owed his loyalty to and had paid the price.
Just to nitpick, that's 40 years out of date. Regular infantry has been issued assault rifles for decades. It hasn't been limited to special forces since Korea.
I'm shocked, shocked that this could possibly be the case, given that this is the WP.