This is a smart move and it is the sort of answer to the question, "do you want a big piece of a small pie or a small piece of a huge pie?" that every founder must decide for themselves. Ultimately the best thing is to put yourself where you can do what is best for your business, but sometimes that means not being in charge.
80 employees. Wow.
Why is this on hacker news front page?
To clarify: Jason is stepping down into a CTO role.
This makes sense. Like he said in the post, as a company grows, the CEO role tends to shrink farther and farther from the technical nitty-gritty.