It's not just that you should not project messy code onto someone's personality/identity, but you also cannot reliably do the inverse. I know people who are meticulously organized in everything they do in real life, who hate to be around a mess, who always want schedules, predictability and stability in their daily life, who optimize their daily routines to perfection. Yet they write lousy code, take shortcuts, do not think the problems they solve through enough, etc. Likewise, I know people who are chaotic in every way, who don't adhere to many of the things almost everyone else considers to be the norm, who have little to no self-discipline for mundane tasks, who are non-conformist by choice, and who are often perfectly aware of these shortcomings. Incidentally, I count myself into this group. Despite all this, I consider the code I write to be very thorough, organized, maintainable, proven to be very resilient to bugs, efficient, etc. The process that gets me there may not be the prettiest, thought-out, elegant process you could imagine, my workspace may be cluttered with 10 terminals, my temp dirs maybe full of old cruft, and so on, but still, I consider the products of my work to have all the qualities I seem to lack in real life.

So apparently, personality really doesn't say much (if anything) about the quality of the software you write. It's a profession that is so far from our daily lives that you cannot project one onto the other or vice versa, exactly like you already wrote.