The problem with this line of reasoning, eg "if you write slow code you're incompetent", is that it applies to everything that programmers do - if you write slow code you're incompetent, if you write buggy code you're incompetent, if you write undocumented code you're incompetent, if you write untested code you're incompetent, if you write code slowly you're incompetent, if you write code that doesn't fulfil all the requirements perfectly you're incompetent, and so on for each and every measure someone dreams up to measure how good code is.
You'll very quickly find there are no competent developers.
The problem with this line of reasoning, eg "if you write slow code you're incompetent", is that it applies to everything that programmers do - if you write slow code you're incompetent, if you write buggy code you're incompetent, if you write undocumented code you're incompetent, if you write untested code you're incompetent, if you write code slowly you're incompetent, if you write code that doesn't fulfil all the requirements perfectly you're incompetent, and so on for each and every measure someone dreams up to measure how good code is.
You'll very quickly find there are no competent developers.