Well, I don't know if the true evils would care, but I don't know whether they'd want to come out and openly admit that they are evil. It might hurt their ability to execute their dastardly deeds.

! True.
Yeah, I don't know whether you can really "change" or "develop" on this system.
It kinda just seems you are one way, and likely probably always have been that way.
Ok, maybe not, I suppose certain shifts could happen in one's life, a la what UniqueMixture said.
But I don't know if those changes would be anything you could or would want to have control over.
It seems like you could kind of have a "conversion" experience to being more good or more evil, tho.
I'm not sure whether people would be as likely to slide on the order vs chaos axis, tho -- maybe...?
I figure maybe you could have some major perspective change that would cause you to shift on the Law-Chaos axis, like going from a conservative fundamentalist household where you were basically subject to your parents' rule and going away to college - I think this happened with a friend of mine; she seems to have moved from Lawful Good to Neutral Good after escaping her parents' indoctrination and discovering the freedom of intellectual society... or maybe the opposite happens, you grow up in a fairly lawless household with a lot of strife and fighting and are Chaotic because that's basically how you learned to live, but you start to grow towards Lawful as you see how order and stability can create peace and harmony...
See, one of the reasons I'm interested in this system is because of dating.
The fact of the matter is, I think I only want to date someone who is good.
Whether lawful, neutral, or chaotic, I'm not as sure; neutral would probably be my top choice.
Between lawful and chaotic: lawful has the stigma of being a boring anal retentive, while chaotics just seem like they might throw too much unnecessary drama/chaos into the mix. I don't know whether individuals of these preferences would necessarily have to hold to these stereotypes, tho. I'm sure there could be cooler and less cool lawfuls, and more manageable and less manageable chaotics.
True. For me, I think wanting to be with someone who is either Neutral or Lawful is like wanting (needing?) to be with someone who is a J - I just know that given my own strengths and weaknesses, my life is going to be a lot smoother and happier if I have a J around. Yes, sometimes I will want to totally overturn their morning routine just because I find the perceived "necessity" of it to them illogical and annoying, but for the most part I will find it endearing and the regularity and sureness of it comforting. And yes sometimes I will want my Lawful or Neutral to say "fuck it all" and run off for the hell of it, but truth be told I don't really want them doing that in my personal life. Not to me. With externals, yes, maybe, but that's just indicative of me wanting a change in my external world and me needing to actually do something about it.
I do know that I
have to be with someone for whom Good is the top priority, over Law. I couldn't handle being with someone who is Lawful over Good, because, like I said, I think law exists to foster good.
I think it's less about sorting people via system and more like you have to learn what is best for you internally and then these systems become shorthand for what you know works for you. Of course you are going to run across a few outliers who are good for you despite their usually unappealing type or bad for you despite their usually appealing type (probably more of the latter), but for the most part, these systems - MBTI, Enneagram, Alignment - get at core perspectives that speak to how you will act and react in every realm of life and the basics of how you operate as a person... MBTI covering how you think; Enneagram how you protect yourself; Alignment what you value most.