If the 6+ is your only computing device and you want something that excels at nothing but is OK at everything, the 6+ is your ticket. Some people want total convergence: phone, tablet, laptop.
Me, I find that the 6+ is big enough that I wouldn't take it everywhere with me and small enough that I couldn't do serious, productive work with it.
I've also go this sneaking suspicion that tablets are not nearly going to be the life-changing product category that people think it will be. A laptop and a keyboard are still just way more productive for the vast majority of people.
It's a sub 5" phone and laptopworld for the foreseeable future. Not bullish on wearables either unless the sensors can truly do something useful.
It's my convoluted way of saying that the 6+ is more of a market filling need rather than a tightly held Apple conviction. Even they did not have the guts to continue selling only a 4" phone.
