People who tend to do cardio aren't exactly very active people outside of the gym. I don't do cardio but most of my hobbies outside of lifting are active ones which I do on weekends. Sometimes I go riding on my 3 wheeler, play football, second job at a moving company, hiking etc... Unless your busy most of the time with personal obligations I see no reason to not use that energy from cardio to pursue active hobbies outside of the gym.