My reasons are similar to yours, Mark.
For many years I commuted in and around London for work. If you've ever been to London, you'll know that the transport system can get a little crazy. I got tired of it.
I've always been interested in working from home, but initially I found that a lot of ads on-line were not legitimate. I searched around and came across oDesk. I didn't sign up immediately because I wasn't sure if it was the real deal, but then I researched it and eventually signed up. (I've now been here for 2 and a half years)
I already had a home office, so I thought 'why not do the same type of work from home?'
I found that I could potentially earn the same, if not more money from home.
I like that fact that I can choose my own schedule, I'm my own boss, I work from the comfort of my own home and I don't have to pay for work clothing, extra lunch or transportation.
Sometimes I play the radio or watch TV while working and I can take as many breaks as I like.
OK, you have to consider the cost of electric, an internet connection and other items for your office, but it's a small price to pay in the long run. Applications like Skype make it easier and fairly cheap to have a phone service.
Filing taxes once a year also isn't that difficult.
I'm also a Singer, Song writer and I have my hands in other pies. I've met some nice clients on-line and I like assisting their businesses. Freelancing works for me.