Two types of people

There are two types of people.

1 - those who get over arguments almost as soon as they've started, apologise for their part in it and get on with things because life's too short (Type C)

2 - those who sulk over an argument for days, weeks, months, years preferring to prolong the BS (Type D)

I've labelled these Type C and Type D.
I'm a Type C as is my mother but quite a few people I know are Type D which is very difficult to reconcile and is pure frustration having to deal with or be around. Because as much as me and my mum may fall out about little things or have bust-ups we're always best friends if not hours later, then definitely by the next day. I don't understand these Type D people and never will. If I had to choose one kind of person I don't like, this is it. The question I ask them is: "Seriously, what's the point of making one bad situation a whole lot more miserable than it has to be?"

I really would like some answers here because its the cause of some BIG problems.