Brewing at home is something I do for fun. I also enjoy hunting/fishing but I sure wouldn't want to be a professional hunting/fishing guide. I guess it's all about the responsibility. I had plenty of responsibility (CEO of company with $30 million gross sales) when I was working (retired now). So if I make a mistake while making 6 gallons of beer, it's just 6 gallons not a big hole in the checkbook.
Right on. What I like about my hobbies is that I'm not dependent on them. If I strike out hunting or fishing, I can just hit the market on the way home. If something doesn't do so well in my garden, then there's always the farmer's market. If I have to dump 3 gallons of beer because it's not something I want to drink 3 gallons of, then it's no big deal.
I am also pretty happy in my career right now, and my family is well taken care of. There's no way I could undertake something that would leave me with less time for my family.
That all said, once my son has flown the nest I would certainly consider taking one of my hobbies a bit more seriously. I have had an idea in my head of applying the brewpub concept to a meadery (or maybe more of a meadhall/brewpub combo). But that's many years down the line for me.