We don't view thickness as a dependency of being called a mattress but that is certainly subjective.
Our 10" version is being released soon so maybe that may (or may not) earn some more credibility with people from the mattress industry, such as yourself and your wife. We were completely opposed to making a thicker bed but the reason we came to justify it was for people who have headboards and don't like the gap exposed above the mattress and the bottom of the board. Or for others who just want the look of something thicker. But comfort wise, it's completely identical to our current version and we'll be very clear about that.
We did thorough testing of mattress thickness and its correlation with comfort when we made our first prototypes. We've built mattresses from all natural cotton and wool, latex, memory foam to what we have now and just could not see any data pointing to it being directly related.
I'd also like to point out that we don't have much support from people who work or have friends in this industry for obvious reasons but that's the path we've chosen.