Hi guys, creator here 
We just launched the service and I think your feedback are extremely important.
As you can guess the main target for HardyPress is the myriad of blogs and “brochure” websites that, most of the time, contain only the pages “Home”, “About Us”, “Services”, “Products”, “News” and “Contacts”. The “dynamic” part of the architecture for all of these sites is only really exploited by admins while navigating in the backend of their CMS, in conjunction with updating their site. For the rest of the time, millions of servers around the world continue to produce each visit the same page produced a second before, and visitors “undergo” a dynamic architecture that only produces negative effects on their experience: slowness, instability, potential vulnerabilities.
So the HardyPress way to simplify things is to use WordPress as a static site generator, as simple as that.
In addition we take care of make contact forms running seamlessly (for now only contact-form7), and augment the search box to provide instant suggestions to visitors.
I’m sure this can be a great benefits for most of the sites 
About security, as maiki said WordPress can be hacked in many ways , but having the server turned off mitigate a lot of problems.
I will be happy to receive your feedback and answer any questions
Claudio