Hi DeRiBas,
I’m not sure who you were talking with there and that’s unfortunate but Scott is very knowledgeable and it may be worthwhile asking to talk with him instead to make sure that the information you are receiving is accurate. They may have been providing information about a different mattress.
The height of a mattress has little meaning in terms of support, comfort, or durability because all of these depend on the specifics of the materials and components inside it much more than the height and the height of a mattress is more of a side effect of the design goal and components in the mattress than a spec that has meaning by itself. Having said that … in a more “apples to apples” comparison between two mattresses where the layers and components are otherwise the same … thicker mattresses can have a greater and more gradual range of compression between softer and firmer as you compress them more deeply which can sometimes be helpful for the mattress to adapt different sleeping positions or for those that are in higher weight ranges so that the mattress doesn’t become too firm too quickly or “feel” like it’s bottoming out (see post #14 here).
I would add a STRONG caution here though not to let height influence you in your decision because this would only be relevant if you were comparing mattresses with the same layers and components (such as 6" of latex to 10" of latex that is the same type and blend and firmness) which isn’t the case here so I would use careful testing to decide which mattress is the best match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) rather than a much less significant or meaningful spec such as the height of the mattress. The durability of a mattress also depends on the type and quality of the materials inside it … not the height (see post #4 here).
Phoenix