A lifestyle business is one that you build to improve peoples' lifestyles (including your own) rather than to make billions. You can give one a 70-hour-per-week effort, or you can automate yourself out of necessity and get passive income.
You don't have to burn lots of hours and take degenerate risks to be passionate about something. I see Valve and Github as lifestyle businesses (proving the culture, not making the global rich list, is part of the goal) but I'm sure the leadership is quite passionate.
The short version: "I Love Lucy" was a lifestyle business dreamed up so that Lucille Ball and her husband could have children. It was easier to revolutionize an industry than have a two career couple and family, so they did. In terms of technical innovation, the show was the "Star Wars" of its day, which is part of why reruns of it still get played to death to this day.
Nope, you're mostly just concerned with your own lifestyle. That's fine, of course. But there's no need to try and make it sound any more noble than it actually is.