As mentioned in the article itself, the RPi Foundation is the charity at the root of the organisation, and RPi Trading is a wholly owned subsidiary of that charity.

I have no links whatsoever to any RPi organisation of any sort, so this is purely guesswork, but I could imagine that operations have grown to the point where they are interfering with (or at least a distraction from) their original educational mission.

Perhaps this move is to offload that distraction and allow them to re-focus on the original idea?

Why must it be assumed that this is a greedy move that works against their mission?