It's not dumb from Apple's point of view, as you say. It's not dumb of me to point out that 16GB is plenty for plenty of people, either. Who needs 32GB on a phone used to make phone calls, snap some pics or send a few texts or emails. We here are not representative of smartphone users in the entire marketplace. Apple knows how their stuff gets used. When 16GB won't cut it, the base storage will get bumped. Or, heh, maybe it will get bumped when the mainstem of Apple's profit margin comes from cars instead of phones...but meanwhile it doesn't make a lot of sense to get all fired up over a decision that belongs to the manufacturer. One still has choices, and can go elsewhere if they're not appealing enough. So far the number of times that happens is apparently not significant enough to force Apple's hand.
It's a dumb argument because you're framing it like people who can live on 16GB are saving money by not having 32GB, but they are not. The only one who wins in this scenario is Apple.