Those that carried extra batteries can just as easily carry an external battery/charger..
Sorry, but to me that oversimplifies the many issues. While it is true that I very much care about the SD Card more, I'd certainly make a buying decision on batteries, too.
First of all, that new "huge" battery in Samsung's propaganda isn't that much bigger than the N4 if reports on the sealed Note 5 are true. (As I recall, about 20-25% bigger capacity. Big deal.)
Second, when a battery that size is drained, fast charging or not, how long is it going to take to charge it? Do you always have that time to wait before going out?
Third, all circumstances are not equal. If you answered "yes," to number 2 for your daily life, that doesn't end the story. On a regular basis, at home, I wouldn't much care if my battery were
smaller. I'm always near a charger and it's easy to top up. The problem is: when I'm NOT in regular circumstances. Today, for example, I'll be going into a sort of pastoral setting. No electrical sockets around! When I'm on a 10 hour plane flight, no electrical sockets. When I'm walking around a foreign city using GPS and the battery is low, I don't want to sit at a cafe for an hour to charge up,if I'm not otherwise going to. OTOH, I can have the back and case off, a new battery in and case and back replaced in less than 30 seconds. Reboot. Done. Nothing's easier and faster than that.
I also don't agree that carrying a charger is as easy as a battery, at least not if it has to be in my pocket. Chargers have prongs. Internationally, add an adapter. And then you have to remember the separate cable, too, and always keep rewinding it so it doesn't sprawl out. A battery overall is way easier to carry--slimmer profile, no muss, no fuss.
And fourth and finally, of course, as many have pointed out over the years, batteries wear out. I am reaching a point where my life cycle for phones isn't going to be every year or even every 2 years. It's a huge inconvenience to have to return the phone to the factory for a new battery instead of just popping a fresh one. Even in a 2 year cycle--I have seen noticeable decline in efficiency over the final 6 months for batteries I had in my S4. What happens if I'm keeping the phone for 3 years?
So, if I can summarize, Samsung, which used these features once upon a time to differentiate itself in the marketplace, now thinks they are worthless. Not coincidentally, if there are no SD cards, Samsung will be forcing many of us to buy phones with huge internal memory. And every time we get a new phone, we'll be paying for the same, pricey internal space over and again. Samsung, though, will make more money from this, as if the phones aren't expensive enough. And then they ditch removable batteries. When the fixed battery dies, we will have little choice but to return it, presumably to Samsung for service ($$) and then to buy the new battery from whoever installs it ($$$). More money yet again to Samsung, increasing the cost of phone ownership overall.
I think that puts it in the proper light.