IMHO, what you propose and cargo pants have only in common that they're pants with pockets, nothing else. So the last paragraph is warranted, even if it seems that some here feel personally attacked by it... The whole point is how the pockets are integrated into the pants, and that's completely different solution than cargo pants.

Anyway, seems neat! I had some work shorts on a summer job years ago, funnily they were mostly like cargo pants, but they had an additional pocked very similar to your proposed one. It could be used for a folding meter stick (or whatever it's called in English) and that pocket alone made the shorts perfect. It allowed easy storage and access to a frequently used tool which was almost unwieldy long.

Do you plan to sell something like this online?