There are a few reasons why I DIY. I'm sure a therapist could analyze me for hours but here's what I came up with
Cost. I save WAY more money doing it myself. If you can get something that looks almost exactly the same as buying it new, or hiring a contractor at more than half the cost in most cases, would you?
I am the baby of my family. I have 4 older brothers and sisters and I'm sure they can vouch that I want to do things myself. I didn't need help getting to the top of the tree when I was younger and now I can certainly hang a sheet of bead board by myself.
Every time I work on a project involving power tools some guy I know (and some I don't) asks me if I need help. By "need help" they mean I'm a chick and shouldn't be using tools. I can read between the lines. The simple fact of the matter is I'm completely capable of using dangerous tools. In fact, I'm probably more careful than most men because I actually read the owners manuals. I don't want some gallant man to come to my aid in the garage and rescue me from a table saw. My husband rescues me by bringing me flowers and taking me antiquing. He doesn't ask me to put down the drill before I hurt someone.
I love trying new things. Sometimes it would be easier to buy something. But if I always did that how would I know how to use power tools? How would I know that muriatic acid makes metal rust? How would I know to turn the light switch off before hanging a light if I didn't electrocute the pee waddle out of myself once? Knowledge is power and I can't take over the world if I don't have any knowledge!!!
I love creating beautiful things. I love the satisfaction or recycling a pile of garbage into something cool. I love working with my hands and feel accomplished when I put in a hard day of renovating or cleaning or landscaping. And I love having my kids along side me in the garage or back yard working on projects. I'm kinda sad for the day all of them will be in school and I won't hear "Why are you banging that?" or "I wanna bang that!" all day long.
That's all I got for now. I'll let you know if I come up with any other reason why I'm as crazy as I am. Feel free to add to it!