Carmack in that link isn't exactly giving unqualified support to your position. The first sentence links to where he's now a big fan of functional programming and supports programming using combinations of pure functions.
Obviously, he's a different person and has a different opinion.
My experience has been that people on HN tend to interpret that part of the posting a little more extrapolatingly than I do. I think he is saying something pretty obvious, which is that when you can structure things in terms of pure functions, you don't have to worry about the side-effects that are one of the main issues you need to contend with when factoring things apart.
This is different from being a "fan of functional programming", i.e. believing you should use current functional programming languages to build your projects, or whatever.
My experience has been that people on HN tend to interpret that part of the posting a little more extrapolatingly than I do. I think he is saying something pretty obvious, which is that when you can structure things in terms of pure functions, you don't have to worry about the side-effects that are one of the main issues you need to contend with when factoring things apart.
This is different from being a "fan of functional programming", i.e. believing you should use current functional programming languages to build your projects, or whatever.