Over the years, the percentage of the NRA's money that comes from members and membership activities has decreased, while the percentage that comes from gun-selling corporations has increased. As that happens, the NRA morphs gradually from a grassroots organization to a PR arm of the gun industry. Effects of this include:
1. The NRA's interest has shifted from an individual's supposed right to own a gun, to corporations' interest in opportunities to make money by selling guns. For example, I think most NRA members do not personally want to own semi-automatics and high capacity magazines, but the NRA has been uncompromising in opposing restrictions on such things because gun companies can make more money if they're allowed to sell a wider range of products.
More interesting, though,
2. Acting as a marketing wing of the gun industry, one of the NRA's new roles is promoting gun sales, which they do by spreading paranoia that your ability to buy guns is about to be restricted. Especially any time a new Democratic president or Congress is elected. More fear = more people rushing to buy guns while they still can.
And even more interesting,
3. Like Super PACs and similar outside groups run "negative" political ads so that the candidate they support doesn't have to take the backlash, the NRA as the gun industry's Super PAC has another role: take the heat off the corporations. Be the lightning rod for criticism, so people don't protest or pressure corporations directly. Seen in this light, saying stupid and offensive and "out of touch" things fits into the NRA's role well.