BHA was created by Trout Unilimited staffers and activists in Oregon for purely political purposes. The overall picture is, of 100 percent sportsmen/hookandbullets, there are about 20 percent who are Fudds, or "spiritual" type hunters who really get into the woo-woo side of being grateful for "Nature's bounty." The other 80 percent are pragmatic hunters, don't feel guilty about shooting a good animal et cetera, and/or they have guns not only in the context of hunting but in its constitutional context.
That 20 percent is not going to support NRA, so BHA is a way to get these 20 percent to actively oppose NRA.

Up hills slow,
Down hills fast
Tonnage first and
Safety last.