When I was working full time in a shop I would spend some time in the evening, or Sunday after a club ride, working on my bikes, but my hobby was riding bikes, not fixing them. Now that I'm effectively retired I seem to spend more time building project bikes in an attempt to encourage us to get out more. I did work one place that was mostly asembling cheap bikes, but I wasn't a good fit there and I had an offer from a proper bike shop - I don't think I would have lasted much longer at the discount place.