Why is there so much turnover in community management?

Earlier today Richard Millington wrote a series of tweets about turnover in community management and theorized why people might be leaving, and if it's a problem or opportunity.  There have been a couple of responses, and I'll be keeping an eye on it if a real conversation gets going.  I hope it does, because it's a big problem that I am wrestling with myself.  Here's a list of my thoughts, in no particular order:

• Pay is all over the map - if you look at jobs on LinkedIn you'll see pay ranges from 30k to 140k. 
• The job is not well defined and as such is a catchall bucket for things that marketing (often) doesn't know how, or want, to do. 
• The ROI when it's done right can be amazing, but it's hard to convince a company to invest, because hiring excellent communicators is expensive.  Excellent communicators who are also Subject Matter Experts even more so.
• Because companies are slow learners, the career path is short. 

I'm a prime example of that last one.  Ten years ago when I started interning for a community manager at a major silicon valley company for a major open source community, she had to explain to me what we did in my interview.  Community Management wasn't really a thing back then. 

I finished my degree in CS, she hired me as an engineer, but I ended up being an administrator and running the community a few years later, and then on through a major corporate acquisition that was really ugly for the community.  It was tough, but we grew in a huge way.  Now I've been "promoted" and I maintain the community infrastructure for the very large tech company that acquired me and try to develop guidelines and best practices for our community managers.  That's all groovy, but I'm not a community manager anymore.  I'm a project manager with a specialty in communities and a vaguely fancy title now.  And there's no place for me to go careerwise, because there are very very few D and C level community oriented positions, and almost none that I've seen outside of tech. 

I have skills, education, years and years of experience.  I'd love to mentor and strategize and be tactical at a high level.  Or be a product manager for a community platform.  I'm highly qualified to do it.  But the jobs and larger community ecosystem aren't there yet.  I think they will be as marketing is transformed by this phenomenon of connectedness.  But they aren't here now.  I'm 43, and if I want more pay, a better title, more responsibility, it seems that I either have to start being a consultant, or I have to leave community behind.