In the US, President Roosevelt was running out of revenue sources to fund his various and sundry programs, so taxing the heck out of certain firearms-related stuff made sense. Hence the NFA.
I seriously doubt that NFA fees have ever generated enough revenue to be a molecule of a drop of water in the vast ocean of the federal budget.
It is a shame that sound moderation is viewed with such a slanted perspective in the US, but it's not an NFA item in order to generate money for the Federal Government.