Sure. Because there are all types of gamers out there. Those who don't roleplay in detail and just use alignment as a stat mechanic won't invest much in it except to make themselves flexible. (Chaotic Neutral is also very popular among those who want to do whatever the hell they want.)
I actually really think through mine and how it specifically will manifest. And I try to make it a consistent psychology. But hey, that's one of my personal interests -- I'm into typology systems and psychology.
For example, I'm developing a lawful good vanara right now (monk), but the vanara are more mischevious and chaotic. So I give her more focus than a vanara might have (she disciplines herself). She also has a good heart and wants to help people when they're hurting or in trouble. her "lawful" is more about "following the natural order" of things, so she perceives an order and then responds to that order, and she might still respect other orders but will challenge exploitative ones. Also, when dealing with evil, she's not the vengeful sort in terms of killing everything; because of the "natural order" she's okay with leaving the natural order dominate the situation. ("You did this; I won't kill you, but I will release you to deal with the ramifications of your behavior and you might not survive that ordeal.")
Another LG character I create might look very different from her. But I typically do not play LG very much.
Or how I was playing Sumiko as NE: "neutral pragmatic," and many of her behaviors "looked" like she was being altruistic but she even would lie to herself about her real self-serving motivations.