One of the rules of capitalism..
Any time a commercial entity (in this case Apple) proposes a change to a current, working system (such as sim cards) it's usually to the monetary benefit (less cost to manufacture & end-user lock-in to vendor) of the entity. One could say the same thing regarding the elimination of the headphone jack or the lightning connector, the list goes on...
Any possible perceived benefit (real or unreal) to the end-user is purely coincidental and seconday to the previous statement - and is used to lauch a publicity war on the users to get them to accept the change without them understanding the true impact and reason it is being made. - Basically most companies don't give a shit about their customers, they only care about extracting maximum profit from the user's personal worth.
You see, it really is just about profit for most companies nowadays - it's not about being the best at something, or providing the best value, it's just about profit anyway they can get it - it doesn't matter how, when, why, who or what.
Do you really think that any cost savings that Apple gets will be passed on to the consumer? I don't think so. More than likely, Apple will turn this into a profit center - after all, specialized software, infrastructure will be needed along with a surcharge - all under the guise of "security".
(non-E) sim cards work just fine, in fact they work too well for Apple's liking..
(As a side note, I keep reading about how millenials can't afford to purchase a home.. I wonder if not spending the $2500-3000 / year that each one spends on having a phone, premium cable, netflix, hulu, CBS, disney subscriptions and the $400/month lease on that brand new car, would help towards a mortgage - you can't have everything - grow up and choose what you really need - and not just something you "want") - For those that are being financially responsible, I apologize.
Flame away, I stand by my convictions..