I think the first question to ask yourself is "What do
YOU
want to do?"
If you did the coding from scratch to bootstrap your product but don't see yourself as a developer in the long term, then it is all fine: you find yourself other responsibilities in your company (and there will be many to take care of) and let your CTO take care of the developments and hires in the tech team.
On the other hand, if you did this to actually learn to be a good developer reuse that skill later (eg. launch another startup later) then you fall into the questions answered in other replies: is it political or is it only about code quality? (If it is about code quality, maybe your CTO is a jerk saying it this way, but for the sake of your product, it can be logical that you'd be out of its developments...)
As from my own experience, my guess is that you are in between those two situations. In my case, here are the reasons why I was:
- it was good fun bootstrapping the product with little constraints (small team, little production code, few processes, 100% reliability not mandatory etc.): I want to keep doing this
- it can be useful to gain experience into the getting big (team, code base, user base etc.) even if it is less fun
As for now, my best answer to this dilemma is to:
1. know you skills really well to know your value
2. keep innovating as much as possible: when being an entrepreneur (cofounder), your first required talent is not to make sure your code is 100% clean/safe etc. neither is it about having hard processes, but to create new things, to trust your ideas and to make them real. As a matter of fact, YOU cofounded your startup, not your CTO, so remember you have this skill and USE IT!