NPB,
I agree with what you're saying, completely. I suppose a loan though, would be more palatable to folks that live in a location where the cost of living is generally lower (and hence, median salary is lower). I suspect this is why Mile High now has a financing service for their AI's (or any high dollar purchase).
Case in point. I ran into Gossett6mm at a match in NM a few years back (he used to shoot at our club before he EAS'ed out of the Corps) and him and his wife and I were talking about something, and a Ford Raptor came down the road. I remarked something to the effect of "nice truck". And G6mm's wife mentioned "Yeah, when we lived in SoCal they were everywhere, but now that we're back in X (midwest), you never see them; which is ironic. Because where we live now, you actually can use them to their potential, whereas in SoCal most of them never saw dirt roads, much less anything 'off road'. The issue is that in the rural midwest, there aren't as many of six digit salaries to support the purchase of $70k pick up truck."
I think the same thing applies to the purchase of high end firearms, optics, etc.. Some folks just need a path to get there, since the local economy just doesn't support the ability to easily fork over that amount of cash in one instance. The market sees a need, and a solution arises...
That being said, saving up is doable, but as you stated, it takes some discipline and patience to get there. Patience (unfortunately) is something that this current younger generation lacks (for the most part) in spades. I don't mean that necessarily as a ding to the millennials (every generation has its primary flaws), only that IMHO, that is one of their more obvious hindrances.