Re: It would be interesting to see the stats..
I tend to agree that the average user really probably doesn't care about a removable battery or SD card.
I used to care and up until a year or so ago, it would have been a deal breaker for me too, but over the last generation of phones I've bothered less and less. I used to always carry spare batteries for my Galaxy Notes 1,2, and 3, but never bothered with my Note 4. Similarly, I used to carry multiple SD cards but now with 64GB+ cards, I don't bother at all and just carry a USBToGo stick (such as this: http://www.amazon.co.uk/Transcend-Stick-JetFlash-32GB-silver/dp/B00SGPG6I6/ref=dp_ob_title_ce )
I can fully understand and sympathise with those for whom these missing features are a deal breaker, but I think they're a relatively small minority now. The vast majority of Android users that I know have never had more than one battery, or changed the SD card (if they even had one in the first place).
That being said, since I've two phone contracts with one up this month, I've preordered a 128GB S6 Edge so that storage won't be a concern.