If Joseph had planned to start with theology, religion or philosophy, Luke would have to be prepared at all times to carry out mental or even physical therapy.
It was impossible without risks.
Steve was the only true product of the super soldier serum, while Dr. Banner had accidentally turned himself into the Hulk.
Compared with magic, these risks were nothing.
If Joseph ever signed a contract with a demon and turned into a Ghost Rider or an evil spirit like Elektra, his soul would be lost after he died, and there was no way to save him.
In comparison, as long as he didn't experiment on himself during scientific research and put all sorts of preventive measures in place, it was relatively safer.
Also, if he wanted to use science to study magic, he would have to be at the top in the world in some subject areas.
This way, no matter how smart Joseph was, it would still take him a decade or two to build a solid foundation.
