Well, I understand why Apple goes for thinner and thinner from a Designers point of view: It just looks super futuristic and nice and even more important: It makes thicker competitors look like ugly stone phones from the last decade. And I have to admit: When I had an iPod touch of the current generation and an iPhone 5(S) next to it in my hands, I really wanted the iPhone to be more like the iPod.
I don't think Apple would design a Phone that doesn't even last a day, but I think they are taking a wrong usage for reference: An iPhone easily lasts a whole day, maybe even 2, but on moderate usage. But on heavy usage it dies faster than a polar bear in the desert... So I really would like Apple to push the battery to a point, where it lasts all day even if I'm in an low coverage area and watching movies or so.
tl:dr : yes
Agreed. I can handle my battery lasting 6 hours whilst WiFi web browsing at home, but when it dies in less than three hours of intensive 3G use whilst out and about, that isn't acceptable.