I really don't understand this story, most tech entrepreneurs with successful companies have to hire people better than them, mark zuckerberg, jack dorsey(especially the twitter guys), snapchat etc. You 2 guys are the founders and hired a CTO and the CTO is telling you to leave, imagine the CTO of snapchat telling Evan Spiegal who cannot code to leave, it just doesn't add up.

If i had to guess, your cofounder who is the business guy realizes that the CTO is a better coder than you and is trying to push you out and offer the CTO a better share of the company. You really need to stand up for yourself, do not limit yourself or feel inferior, i mean even Larry and Sergey had to get better programmers than them.