I've been cutting my own hair since about 10 years now.

Here are my reasons:

It's close to home and it's easier for me to get there; in fact it IS home!
I have established a good relationship with the person since I became aware of myself, being about 2 years of age;
I know exactly how I want my hair to look;
I love the feeling I feel when I get my hand through my hair;
I love that massage on my head and neck, which I sometimes do after haircut;
I like that I always have a fresh breath;
It's much cheaper than all these modern saloons with so called stylists. - Scrap that - it's downright FREE for me.

:D