I know that not having enough content sucks, but isn't it better to just come back when an expansion launchs, play all that new content, and then take a break again for a few months?
Do you really want them to trickle down content like that, just so you stay subscribed?
Let's say they release Nighthold in January 2017, and release 7.1 with Karazhan and Trial of Valor (or what it was called, the additional 3 boss raid) somewhere in between Emerald Dream and Nighthold, so maybe December... you'll have a steady stream of content, but it will be little bit by little bit for half a year. Making you stay subscribed for 6 months. Is that really worth the money for the subscription?
I don't know, I kinda like that there was such a long content gap, because it allowed me to say, you know what, there is nothing to do for now, so let's take a break for a year.
That was money saved and time I could spent on something else. Instead of staying subbed for some small additional 3 boss raid or another 5 man, that I will be done with after a couple of hours anyway.
Let's face it, the amount of content they add in patches is minimal compared to the amount of content added with the launch of the expansion.