I'm not sure I'd personally suggest that hoovering the house is an "excellent" form of exercise, but at least they didn't blindly assume the person was going to the gym purely because they were not aware how to exercise outside of it. Perhaps the community aspect of their gym is what attracts them. None of the replies actualy answer the original question of are gyms are a particularly bad place to go. I would suggest they absolutely are a bad idea as they involve a lot of air conditioning and a lot of shared surfaces. And also a lot of coughing even at the best of the times.