Cardio machines are innocent enough, as they won’t actually make you any less fit, but maintaining cardiovascular fitness doesn’t really take much more than breathing uncomfortably hard for about 20 minutes, three times a week. And we all know that swimming, hoops, bike riding, and even Ultimate Frisbee can get the job done, and that treadmills or elliptical trainers are a pale substitute.
I think the author is overlooking one of the great benefits of elliptical trainers. They get the job done and they're very safe. If you're an obese out of shape person you're unlikely to get hurt getting your cardio in on an elliptical, whereas activities like hoops, bike riding, and Ultimate Frisbee can really fuck you up.
If you wear a heart monitor and keep your HR in the appropriate zones the elliptical can be a safe, effective cardio workout. I spent three years doing hour long cardio sessions 3-5 days a week, with around 60% of that hour spent in the high end of the aerobic zone. At the end of it I had lost a considerable amount of weight, and I had a resting HR of 38.