Could it be, perhaps, that the reason the market is limited, is because the devs have worked so hard to take away a proper sandbox experience? There are so many arbitrary rules and hidden mechanics that the curve isn't something that the average gamer would put up with, and much is perpetuated simply because, GASP!, reasons.
Maybe the dev hours could be better spent by giving us more materials to use the pickaxe on, instead of putting in new rocks and forcing us to buy another pickaxe. Do you know how long we've been putting up with dumb event popups? And yet, they just finally got around to making the choices more meaningful. They admitted that what we had to work with before was stupid, similar to how they now call the EU3 sliders a poor idea, but that won't stop their defense of monarch mana points. They will flip their position again in a few years without explanation, no doubt. If they can overhaul the development building system, then why not mana? How long were the terrain stat boxes overly complex and obtuse? They didn't do anything worthwhile, yet they spent their hours on it anyway. They let us argue back and forth about how this and that didn't make sense and finally revealed that the box was actively lying to us. How much longer are we going to have to put up with just because comets, a stigma based around 3 stability being taboo, coalitions, and unlawful territory debuffs?