I like to really understand what is going on under the hood. If I don't quite understand how something works I like to read the source code. Also sometimes a plugin doesn't quite do exactly what I want, or is so large and complex due to trying to cater for everyone that I just feel uneasy about using it and so for simple things I prefer to just write a little code that does exactly what I need and no more.

Plus, I am a coder. And coders code so that's what I do. It's just a psychological thing...