This is an excellent map of the problem, Chris -- and a timely one for me personally, since I'm in the middle of overhauling my own website to reflect the fact that writing is now my primary gig.

What I think you're missing here is that the most effective solutions will solve for the pain points among both writers and readers. You're seeing this through the reader's lens -- and I know these pain points well, too, because I'm frequently frustrated trying to follow my favorite writers. (One reader-side pain point you didn't capture: Could I please get a one-stop subscription that lets me know when any of my favorite journalists or authors are speaking in town -- or in a nearby city?)

But from a writer's point of view, the pain points look quite different. The problem that most writers are trying to solve for is not, "how do I keep in touch with my fans?" but rather, "how do I sell my work to editors?" (Social media-savvy writers know that the former can help with the latter....but it's tricky to create a website that speaks to readers while also serving the specific needs of editors. IMHO Rebecca Solnit (http://rebeccasolnit.net/) does a nice job of it.

What MOST writers are looking for, it seems, is a way to organize and showcase their portfolio to editors. There are many web services that are trying to solve that problem, like Muck Ruck, Contently and Clippings.me. None of them work very well for someone like me, however, because (a) they don't make it easy to showcase other parts of your work/services, if they allow for it at all, and (b) I'm too much of a tech nerd/control freak to live within their confines. I'd be a lot happier with a Wordpress portfolio plugin, but I haven't found one that's designed specifically for writing portfolios, and portfolio plugins for photography or client projects speak to quite different requirements.

It seems to me that there is a market opportunity here for one of the (many) portfolio services to differentiate itself by solving for fan/publicity needs as well as editor/pitching needs. But that will be tricky, because there are a couple of related ways writer/fan priorities differ from editor/publication priorities:
1) As a writer, I want to show my past work to the editors I'm pitching, even if that past work is behind a paywall. If I have a portfolio site that's aimed exclusively at editors, and if I'm using some noindex witchcraft (trickier and tricker!) I don't mind putting a PDF of my paywalled work on my website so that editors can see it in my portfolio. (The editors of the publications I'm PDFing might feel differently!) But a print-from-screen PDF is not a good way of presenting my work to readers, and also, would piss my editors off if I was end-running their paywalls.
2) Ultimately, editors want people to follow the publication, not the writer. Editors hire me to write for them because they want me to build THEIR readership, not mine. Now, if I have fans I bring with me, that's great. But if people only visit the WSJ or The Verge to read my story, and click away, that's not a big win. My editors -- aka my customers, aka the people who pay my bills -- don't really want me to be driving subscriptions on MY site, they want me to drive subscriptions on THEIRS.

Now it looks like something like PressForward (which I appreciate you putting me onto!) may make this less a non-zero/sum game. But I do think that any scalable and sustainable solution here will need to consider and satisfy the interdependent needs of readers, writers and editors.

And sometimes these conflict in really practical ways: For example, many professionals advise that a writing portfolio contain ONLY a writer's best work, or that it be organized thematically to reflect the different themes you right about. But if you're building a reader-oriented subscription, presumably you want it to be chronological and all-encompassing. I'm trying to reconcile these on my own site by having a chronologically organized blog that posts every link as it goes live, and then a thematically organized "best of" page, which uses tags ("Top Cybersecurity", "Top Tech Parenting") to determine which posts make it onto the portfolio page and where they show up. But that is not a feature I've seen on any portfolio site to date. Again, maybe that's a market opportunity!