Well, the year old part makes it sound much worse than it is. The M8 will release on at&t as a flagship tomorrow with the exact same processor. The snapdragon 800 is still a current, high end processor for a mobile phone. The size is the only "controversial" part of the decision for many people, but it is an experiment that many people are making. A 6 inch smartphone is now available for the first time in the 3 smartphone platforms, Android (where the phablet was born) has a bunch of choices, the iPhone 6+ and the 1520. I think a lot of people are buying one for the first time to see if it is something that they would like.
It is an appealing choice for us because our choices are somewhat limited. The 930 isn't offically available in the states, and I just got LTE coverage in my area, I wouldn't give it up for a handset, even if it had really good HSPA+. The M8 is a nice phone, but I know that I was a little uncomfortable with the idea of buying an HTC phone. It's probably fine, but I want a Nokia. I want the Nokia apps, I want the Nokia camera, and I want Qi charging.
Semi-related sidebar: While I'd suspect that the iphone 6 is outselling the 6+, probably by a large degree, I have personally not seen a single iphone 6, but I have seen three iphone 6+ handsets in the wild.