Now that I got myself reamed (mostly) on purpose, hopefully that'll keeps someone else from asking the silly questions!
The "is there really though" comment was aimed specifically at the "huge" part of your claim, not a statement against the fact that there is a market for it. The reason why I asked was because this is the first case I've ever seen from any common/popular case manufacturer that I would dare call harsh environment friendly. I know it's begging the question and I believe in challenging convention which is what Silverstone set out to do with this case, but I've really not seen anything else like the MM01 before and wonder why that is if the market is there.
A passively cooled, fully encased, water proof and dust proof marine computer (probably IP56) is not a fair comparison at all to this case, as that kind of rugged enclosure is held to a significantly higher standard of protection and build "quality" to maintain that standard of protection. In addition to the often much higher costs for the enclosure itself (regardless of size), custom parts are often used, often times being the motherboard and heatsink. That also drives up the price significantly for these units. Like in yesteryear regarding ITX size computers, you were and still are (for industrial computers) paying for the form factor. The rugged service tablet PCs we have are first gen i5s, though replacements have been second gen i5s. However, because of their impact and dust resistance, as well as the large amount of custom hardware built into unit, the things are over $2000 each.
I looked up the testing documents for the case, and the case was tested (and passed) for IP43, which is very good compared to any normal style case, but not what I would really call rugged; it's somewhere in between and slots perfectly for your dairy industry friends. Of course, that was a calculated compromise as some airflow is practically required for modern PC level hardware, even power efficient hardware. Speaking of which, your testing hardware appears to use a processor and graphics card from from 2010, unless you ran your tests with that 290x you slotted in on page 2. While that's not as old as what is installed on the marine computer you linked, the purpose of the two computers are completely different, for completely different harsh environments.
Do you work in a harsh environment for computer systems? Do you require a case that can keep dust and moisture out while keeping high-end modern hardware safe inside? If not then this isn’t designed for you.
Does a mix of 60 desktop/SFF computers in a few murky, dusty vehicle service departments count? I mean in the workshop, not storefront. Even with the airflow requirements to provide a safe breathing environment for the technicians and the daily cleaning, those places are disgusting for PC hardware. These systems are usually closed behind a cabinet door at each bay (which this case would not fit in by a long shot), but the computers in there still get pretty gnarly with dust and grime. The grime really surprises me actually. However for the work they do, and the work I'd imagine many industrial sectors do, they DON'T need modern, high end software. As a loaded, specific example I don't think most people are running full CAD software on a fully vetted design system next to the rotary tool that's cutting parts out on the manufacturing floor. I can think of two people that would like that ability, now that I think about it ha ha...
Lastly, the mention of the enthusiast market should not have been made. I knew that was not what the MM01 was intended for to begin with and the comment was utter nonsense, my apologies.