Its because Aquarius is such a sign of psychological development and Saturn with Ketu there will focus on that sign a lot.
Of course, I understand what Aquarius stands for, I'm aware of the basics!
Perhaps my point isn't clear, So let me elaborate.
You've mentioned on multiple occasions that Saturn-Ketu is good for growth, because those people automatically move toward Rahu rather than being stuck in Ketu castle.
I took that to mean that Saturn-Ketu in Aquarius would move and work more on Leo, and not be stuck on Ketu.
I was trying to correlate that with the examples I know who largely remained in the realm of Aquarius for most of their lives.
WHen ketu's lord is with saturn they stay more on the ketu side.
Sorry, what I meant to say is that when ketu is with its lord, saturn in this case, its stays on the ketu side.