Malazan Empire: Lamora - Viewing Profile - Malazan Empire

So I was lucky enough to get the audiobooks of most of the series in the recent Cyber Monday sale. I have made it to Deadhouse Gates and I am about halfway through. The more I read though the more I question why the conquest of 7 Cities happened in the first place? The entire land is filled with tribes and grudges and powerful high mages (one of the main battles to conquer 1 of the 7 Cities was considered the largest source of sorcery the empire faced in battle). The slaughter of Malazan citizens in the entire land is almost complete besides Aren itself. Tens of thousands were killed because the normal citizens of 7 Cities hates Malazans so much. Its a hatred that has lasted decades. Every tribe seems to stew in hatred for each other or the Malazans. It just doesn't seem to be any reason to conquer the subcontinent besides Kellenved just wanting to conquer something? Besides maybe Otataral is there anything good about 7 Cities? Maybe they needed it for grain? I can't remember correctly on that one. Genabackis at least has Darujhistan as the jewel the Empire wants. But is there any real reason given for the taking of 7 Cities?