I've always found clean code to be faster to develop. I find that developers that produce lower quality code tend to spend their days debugging, fighting their code, reading and trying to figure out what they wrote 5 months ago, and so on. They are just not very productive. There are the outliers - people that have instant recall of all their code and elaborate mental models of really poorly structured code - but by and large I find that people that generate low quality code are quite slow performers.
I've worked in very good code bases, and very bad ones. In the good ones you can easily figure out what is going on, quickly make changes, confident that you aren't breaking 5 things because things are decoupled. You can produce new code quickly because you aren't fiddling with code nested 6 if statements deep, which is just about impossible to model correctly in your head. You aren't in endless compile/run/debug (or REPL/run/debug) cycles because your first try is usually just about right, because you can understand the surrounding code. I recently requested a simple feature, and was told it would take a week. I was dubious. Then I looked at the code, and decided that they were being conservative, if anything... for something I thought would reasonably take a few hours.
This is just an impassioned plea, not to Jach, but to the profession, to cast a critical eye on code. You can produce high quality code quickly. Not "nuclear reactor" quality, but pretty close. Bad code always costs you. Always. Don't write that way, don't allow it in your code base, or in your teammates.