Agreed. This is definitely one of the hardest decisions I've made in the last 2 years. I did the "work in my free time" thing, albeit on another project, and had difficulty with the work life balance. In the end, the other project successful enough that I'm able to afford to quit (for a short while) and go full time on this idea. I actually finished the second edit of a new blog post earlier today suggesting that folks bootstrap their first startup for some of the same reasons you bring up.