I’m always perplexed by folks who insist on carrying their entire music or photo library on their phone yet these same people won’t spend a few extra $ to have everything safely backed up in the cloud and then lose their mind when something happens to their device and they lose everything.
I'm not saying I'm one of these people, but considering one of the big selling points of buying a big phone with a brilliant display is so you can show other people photos/movies/etc when you go somewhere. Just because they are on your phone does not bean they are not backed up somewhere else, like a desktop, or a notebook you left at home to travel light. Yes, cloud storage is cheap (sometimes free) but mobile internet is expensive. Streaming media on-the-go is often impossible, and usually unreasonably expensive in many places (such as Australia, where everyone seems to own an iPhone X).
I don’t begrudge anyone wanting/choosing to have a larger amount of on device storage but the overwhelming majority of people don’t need the higher tier and I prefer not to subsidize it for the minority who do with a more expensive base option.
I understand and agree that Apple shouldn't be forcing people to pay for much more than they need unnecessarily, which is the undertone of this thread: Apple seem to be purposefully avoiding 128GB to force people who aren't comfortable with 64, up to 256. This, coupled with the exorbitant price Apple puts on storage, causes frustration at Apple. SSD storage has not cost US$1/GB for a very long time. Not even close, probably closer to 20c/GB for Apple.
So, we can all jump up and down in joy when Apple up-sells it's very overpriced storage because Apple's profit and stock might increase imperceptibly, but unless one has an awful amount of money invested (to the point where money would be meaningless for them) that is not going to offset the personal loss of inflated storage costs when buying a new phone.
So, ways that Apple could make everyone happy is to either release all storage tiers (64, 128, 256 and 512), although that would be seen by some as overcomplicated. Otherwise, Apple could reduce the cost of storage upgrades. If not, the (pre-tax, etc.) price of the 512 IPXs+ is likely to be US$1350, possibly more. That is going to lead to a lot of bad press, some justified, some not (just like for the "$10k+" MBP).