I recently joined a community related to Internet Marketing and I am finding it very useful. One of the topics that comes up a great deal is what tools folks use to investigate content gaps. I've been a Moz subscriber for quite some time and understand that, compared to many of its competitors, it's a high end solution. So, feel pretty well positioned there.
However, one thing that appears to be lacking is what might be called a long tail discovery tool. I am well aware of Google's Keyword Planner and other free stuff (the problem there being... so are my competitors :)). But there are a number of tools out there - SEMRush, Long Tail Premium, Authority Metrics and so on - that focus very directly on that, with "scores" for keyword competitiveness that at least help narrow down to a possible set, using filtering.
While I accept that one might argue the merits - or otherwise - of each of these specific tools, it causes me to wonder why Moz doesn't have such a capability. I see some very successful web site owners describing their processes in the aforementioned community and long tail analysis is a key part of that.
It seems that Moz has a richness of features, including around keyword ranking. But it's not clear to me why it doesn't support long tail keyword discovery "directly" (as a specific feature). I really don't want to pay for another subscription 
Thoughts?
Thanks.
Mark