There are lots of reasons folks like do-it-yourself projects. Maybe you're crafty and find it fun. Maybe you're thrifty and it saves lots of money. Or maybe you're like me.
Maybe, you're a control freak and can't imagine surrendering a project to someone else. That's how I end up doing 98% of the DIY projects that I take on. I have an idea of what I want and prefer to carry out that idea rather than try to accurately convey it to someone else. It may in part be laziness in communication, but I honestly think it boils down to borderline neurosis.
If someone else is doing a project in my home, I simply cannot relax. Whether creative or mundane, if I'm doing it (even if it takes four times longer) I'm much happier and more at ease. In fact, to me, the slower pace of doing a project yourself is comforting. The time it takes to problem-solve, learn a technique, or shop for materials is sometimes exactly what's needed for me to make up my mind about particular design decisions.
For better or worse, the control that comes with it is ultimately why I DIY.
Whew, now that I've got that off my chest, why do you DIY?