Apple HAS to stop this 16gb nonsense on their entry level iOS devices. They simply cannot offer an iPad Pro with 16gb - especially when there isn't an SD card slot.
You do realize exactly why Apple keep the 16GB model don't you?
It's about making more money from people.
It's a marketing trick that's been used for years, in many areas esp the food industry and you much of seen this yourself many times
You, as a maker want the most money from the customer.
You need to work out how you are going to do this.
The key point here, and how it works is that the cost to you of the product is far far less than the price you sell it for.
So, let's say you want 100 dollars from the customer, but you know they don't really want to part with 100 dollars.
What you do is to create a version of your product that is a poorer version and price it at say $80 which is the price you know the customers want to pay.
You then offer a much enhanced version at $100, but the difference to you is minimal.
The customers come to the store thinking yes, $80 is my price point, it's what I wish to pay.
Then they come to the sales stand and see the 2 options.
$80 and $100
They note the $100 is a lot better. They think oh dam, did not really want to pay $100, but I'm here now, and look how much better the $100 is.
I know if I buy the $80 version, it's going to be on my mind now as soon as I get home, I should of just spent that extra $20.
I know I'm going to regret it....
Oh dammit, I better get the $100 version, after all, what's $20.
Win Win for the maker.... They sold you the model they had planned on selling you all the time.
That's why Apple are keeping the 16GB model, THEN offering you a 64GB model for a bit more, as they want more people to pay more to get the better version.
It's all clever and as customers we all do it.
The old buy 2 get one free offers in food shops.
Buy a packet that's got 5x the amount inside for only twice the price.
Humans are generally quite logical things, and will go for the best deal and will think ahead a bit.
They know this and use this to get the most money from us.
As I said, this ONLY works when it costs them a minimal amount for the product.