Perfection is a strange concept anyway. Because essentially it's a subjective thing: what's perfect to one person doesn't have to be to another. Yet as a whole I think it's what humanity always strives for. Which is strange, because when you lived long enough, you realize there are very few things that are perfect, if any at all.
For me it also has to do with 'order'. Of all King's stories the one that resonates with me most is 'N'. When you have O.C.D. you seem to strive for a certain perfection too. You derive a certain satisfaction from the idea that everything is in order, and nothing is wrong. You check things over and over, to see if they still are okay.
I don't know what causes O.C.D. exactly, but it feels not simply like being a control-freak. It's just that you want things to be very perfect and derive comfort from that somehow. And the reason feels to me that life at large feels chaotic and messy - you want to make sure at least the things you have control over are fine and you hate it when they're not. It's not that you want obsessive control over everything, but when you come across something that is perfect, or goes well, you derive satisfaction from that, and you basically wish everything could always be like that - which in reality it isn't.
The thing though is that perfection is a human concept I think. I wouldn't be surprised if ultimately it exists because it makes humans feel like they triumph over that chaos. Yet what seems chaos to us, probably isn't at all: the universe exists and works, just not by our criterion of what perfection is. When there is something that is very beautiful and perfect to us, like say a flower, it's very easy for this world to destroy it - by a force of nature for example, or simply stepping on it. And even when it lives, eventually it will wither and die. This does not correspond with our idea of perfection, yet it is the way the universe works. Basically every time we strive for perfection we battle the way the universe works. Just like in 'N', where the guy just tries to stop the chaos from coming through by making sure everything is ordered and okay,