I think your position seems reasonable, too. Though intuitive, it isn't the reality.
The tax-exempt status is granted for Exempt Purposes, but not as a matter of altruistic intention: https://www.irs.gov/charities-non-profits/charitable-organiz...
For example, ask your favorite LLM search engine: Can you list non-profits/501(c)(3) that are US defense contractors?
Draper Laboratory and Energetics Technology Center are registered 501(c)(3) corporations. Their primary output is weapons research. RAND Corp, whose name you'd likely recognize, is also a DoD contractor and 501(c)(3).
The NRA Foundation and the Heritage Foundation are also registered as 501(c)(3).
> The NRA Foundation and the Heritage Foundation are also registered as 501(c)(3).
Yeah, organizations like think tanks (Heritage Foundation) are supposed to influence policy/public thought/elite thought. That’s obviously not a for-profit enterprise.
EDIT: My personal feelings about conservative think tanks aside: any and all think tanks are supposed to spread ideas. The altruism is where in that goal? It could be evil, good, neutral. It’s simply a not-for-profit enterprise.
It’s a bit hard to wrap my head around this original idea of altruistic non-profits.
You will see that in your link "charitable" is printed in bold. Yes, other "exempt purposes" are tacked onto that in US law, if that is reasonable I leave up to you.
Given that the NRA counts as a non-profit, not sure there is anything reasonable about giving them tax breaks. But hey, you also voted for Trump. Twice.