Risk.
It all comes down to how risk adverse you are. Personally, I'm pretty damned risk adverse for most things - my personal motto being "Zero liabilities." That said, I
cannot keep taking orders from other people for the rest of my life. I'm fairly young, but I knew 10 years ago that I would only be able to work for others for a limited amount of time. I'm hitting that endpoint now, and I've yet to make the kind of money I know I can make if I were to work for myself.
I'm going to do this. Succeed or fail, I will have tried. That way, I live with no regrets. My hometown is ripe for craft beer. I have the drive, the resources, the patience and the market to viably brew for a living. I don't care if I never own an Aston Martin (okay, I do...), but so long as I did what my entrepreneur father did - keep a roof over our heads, put food on the table and clothes on our backs - I'll be happy.
No job I've ever worked has stayed interesting or fun for me for long. I've always lost motivation, and that was invariably because the people "above" me made decisions that I knew to be wrong. So I see no difference in taking homebrewing and turning into a business than I did with taking my self-acquired IT knowledge and turning it into my current job - with the extremely large and very-important exception that I'd be my own boss.
I don't want kids, so perhaps that factors in to how much risk I'm able to take on. If I fail, I'm only failing myself (and perhaps a future ex-wife
).