this is exactly what I'm talking about: a marketing team should be able to discuss with you and your customer and find out what are the improvements we need to satisfy real world requirements.
that process must be done incrementally with good planning and feedback, first as add-ons (like Dexterity or Mosaic), to allow people test in real world scenarios the solutions we are proving; when those solutions are mature enough, we can think on including them on the core, not before.
this process has the advantage of being easier and faster, as it doesn't involve all the inconveniences that play against releasing with Plone as a product; more or less the same we had with Dexterity that was available for a couple of years (since Plone 4.1, IIRC) before being part of the core and, finally, become the default content types framework on Plone 5.
so, why are those people not present on the conferences, for instance? they are the ones that should be deciding the new features, not the framework team.
why don't you invite your customer to Sorrento to discuss about the future of Plone?
having said that I have to add that I'm quite happy with Plone and I recommend it to everybody that needs a medium to large website; I don't want to replace WordPress and I'm totally fine with that: we have many, many sites running Plone over here in the Government and, sadly, I'm not going to recommend upgrades until we have a good reason for that.
Plone 6 seems to be a good reason, because it will provide backend enhancements worthing the move (Python 3 support is a matter of life or death) and maybe one or two good UI enhancements.
on the other side, for us, that was never the case with Plone 5, and I have said that many times in the past: I don't have requirements for fancy frontends made with JS (at least, not yet) and I can have all the other goodies without the headaches of a bad designed toolbar or buggy resource registry.
our customers want a CMS that works, fast, reliable and securely; Plone 4.3 gives me that, period. I can build the features they want on top of that and I've been doing that for years now.
we have different views, Dylan: you seem to think that people will come here to work with Plone in hordes if we do this or that; I don't see that happening in my lifetime.
Plone and Zope are boring and, again, I'm totally fine with that: it pay the bills doing a pretty decent job; does that means I don't care? no; can it be better? yes, of course.
resuming, we have different markets, requirements, and points of view; you should accept and respect that, and discuss and listen more, to avoid playing against the rest of us.
good night and good luck!