I don't think it is that clear, businesses that people to devote their lives to also get called lifestyle businesses. People that aren't taking big rounds of funding, only reinvesting profits. People that don't intend to IPO or be acquired, rather are building a sustainable business.
Whether that is the official definition or not, that seems to be the distinction I have seen around here.
If you want to devote your life to creating and running a world changing business, do it.
If you want to devote your life to your family and kids, and use a "lifestyle business" to fund it all, do it.
Just remember one is not better than the other. To each his /her own.