What follows is a hot take from your front page. These are not equal points, just a string of observations:
- “No need to upgrade WordPress or plugins.” - don’t say that. You want folks to keep updated, for a variety of reasons. The number one reason being their ability to get support from the general community; asking for version is an early step in troubleshooting.
- Instant search out of the box - how do you scrap this, and how do you override the search box? I would use the various JSON endpoints to populate the index, wondering if you folks did the same.
- Support for Contact Forms 7 - next should be Gravity Forms, and then Ninja and/or Caldera.
- “If your site needs comments, just install the Disqus plugin, it’s the best way to manage comments in your website anyway :)” - Don’t say that. Disqus is a horrible way to manage comments. I know you don’t have a lot of options, but don’t endorse Disqus, they make web conversations worse, and insert ads and track folks and etc. etc.
- Comments? Disqus to the rescue! - Look into the various static site commenting systems. In particular, consider contributing documentation for setting up WordPress with Discourse!
- “Never update WordPress again” - ooh, we just might have a major disagreement, if that is a selling point. What pain point are you addressing here? Also, how do you keep updates from running automatically? Do folks have the option to auto-update their own sites?
I’d be a lot more supportive of your product if it didn’t encourage not upgrading.
I get the rhetoric, but consider there are two caching plugins in the top 20 public repo plugins by popularity, and nearly every WordPress hosting company has one or more caching layers in front of every site they host, and those “millions” of servers are not just targets for malicious folks; they essentially serve up static sites, while keeping the “dynamic” parts.
About those dynamic parts! Let’s put aside the big ones: comments, native search and ecommerce. Here are a handful of dynamic parts my partners use:
- Responses - these include comments, but also social media reactions, pingbacks, and webmentions.
- Sorting/filters - this can be considered a type of search, but aside from dynamic facets, you also have little WordPress hacks folks enjoy, like
example.com/tags/reference+plugin. - Integration/API - no webhooks being received or sent, so no chat notifications, no discounts given, no signing off on a contact form action. Polling feeds is possible, of course, but no CRUD.
- CTA - A call to action normally triggers something aside from a page load.
- Fundraising - While possible to embed PayPal or even Stripe, my clients are both handsome and prefer hosting their own donation/funding forms and processes.
- Teams - I host the blogs for a handful of friends, but everyone else is a team.
Now of course that list also shows where I am coming from. I just can’t imagine anyone I would work with that would benefit from the level of CMS separation HardyPress provides.
Also, in passing, when I click on “support” from the footer on your homepage, I get the following page:
That’s just kinda weird. 
Looking forward to your repsonses, and thanks for coming by to discuss. 