Thank the NRA. They supported the NFA.
The NRA didn't get into politics until after the passage of the NFA in 1934. They didn't get into actual lobbying until even later than that. Up until 1934 the NRA did marksmanship/shooting sport promotion and little else.
If you have information about the political activites of the NRA related to or leading up to the passage of the NFA I would love to see it.
It may well be that the NRA leadership in 1934 was in favor of the passage of the NFA (although it appears that the sole supporting evidence for this idea is an article written more than 3 decades later), but I've not seen any evidence at all that indicates they actually DID anything in support of it. In fact, all the evidence indicates that they did nothing at all related to politics leading up to the NFA passage.
Which means that the idea that we should "thank the NRA" for the NFA is completely baseless.