User blog comment:Tiredman2/Mass Effect Plot Holes and Contradictions/@comment-1900300-20120821064837

Actually the Code is refring to true colonisation after the First contact war. That is highlighted in the page.

As to the lack of use on the planet there are in fact numerous reasons for this. The main focus of the planet is and trade to the nearby Citadel. Firstly earlier species ould not require a nearby planet fro such because they could operate in the Citadel itself. Or their terriory made it inefficent to use the planet as a trading station rather then just delivery or space stations. The asari and salarians didnt need it, the volus wouldnt want it due to the atmosphere, the krogan were not inclined to see its value and the turians are piggybacking on the volus economic success, not to mention not being economically inclined sd species. The elcor are too slow to seize oppertunites and have limited trade and the hanar seem more focused in their own territory not to mention it may not be humid enough.

Also a planet like this may have been tried up from colonisation for a number of reasons. Political squabbling, trade fears about competition being formed and changing things and military interest in its postion so close to the Citadel may have made it off limits for a long time.

Lastly the fact the planet is used for trading mostly and needs supplys from off world means it has little in the way of natural resourses, another way it may have been overlooked.