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).
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.
> 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.