Kadi's plan hasn't reached the execution stage yet; everything he does now is merely preliminary preparation.
It's true that everything has a spirit, but spiritual power isn't something you can see just by claiming it's there; you need to have the perception for it.
But when it comes to perception, it's hard to say. Talent varies, some are suited for it and some aren't, some grasp perceptive skills like Numerical Sensing in a snap, yet some can't learn no matter how they're taught. This is the disparity, a kind of disparity in spirit sensing, and no one knows what exactly causes these differences, but people tend to draw conclusions.
The conclusion drawn is that some people just aren't suited for the spirit power system and they get eliminated right away.
In terms of talent, Kadi is considered lower among people.
Even Slayer Kuren from Guru Mountain said Kadi could never enter the Inner World...
After all, Kadi struggles to perceive spiritual power.
