Here is my take,
The iPhone 6 is a usable phone. Most of those that are going to buy the new iPhone are those that are already heavily invested with iTunes and other Apple cloud services.
The 6 is a incremental step up, and nothing revolutionary at all. What I think most people that are either disappointed with or poking fun at, is the price versus hardware specs of the device. It's a device at a flagship cost without the current flagship device specs that pretty much every other company is offering. It's a bit behind on camera, battery, cpu, gpu, memory, pixel density, bezel size, and storage specs compared with any of the latest android offerings.
Still, that isn't much of a surprise because hardware-wise, Mac have forever been behind PC's in term of hardware specs, yet cost far more on average than any similar PC.
What was the difference in price for Macs was their "style" difference between a PC and a Mac. Sure the hardware was behind, but the software was decent, in some cases a little better, and the designs of the devices looked nice or hard slightly better user friendly functionality.
The new iPhone just really doesn't do anything right. It's not exceptionally stylish (not with those huge bezels), not exceptionally user friendly (again massive bezels and weight), and the hardware is pretty far behind compared to the normal slightly behind in terms of the competition. The software isn't any sleeker, nicer, or user friendly compared to the latest incarnations of Android. It just doesn't do anything that shines at all compared to any of the flagship competition. The only thing it has that most other phones don't is a finger print reader. Finger print readers have been around on tiny devices for a long time. They are nothing new.
If the new iPhone 6 had a better pricing scheme, I wouldn't be poking as much fun at it. The current asking price IMHO is silly though for the device as it currently stands.