It is an inalienable right. Something the Founders understood that existed even bore pen touched paper when the Constitution was drafted. Some beleive it is a God given right (as I do) and other beleive it is a human right.
I gotta say this, because I'm a stickler this way.
But "the Founders" said no such thing. The First Congress did, because the thirteen states who ratified the Constitution were insistent about the inclusion of a bill of rights. And every state had their own list which they wanted to see in that bill of rights.
Interestingly, while most (if not all, I don't remember for sure) DID include the RKBA as part of their lists, two states in particular were so adamant about this that they said "We'll ratify this Constitution, but if this (meaning not just a bill of rights, but the RKBA specifically) isn't addressed to our satisfaction in the First Congress we're packing our bags and leaving."
Those two states were North Carolina and (ironically, today) New York.
And you're right...by and large, the average gun owner is apathetic about taking actual action. But to be fair, this is human nature across the board, whether talking about politics, religion, or anything else. Most people just want to go about their business living their lives and being left alone. They're busy with other things in their lives, whatever those things may be, and unless there's an immediate and direct impact on them, it gets buried under other priorities.