'outdoor' exerciser machines

Being early for my swimming pool lane booking, I was wandering around the gym complex.  This is the setup for people who want to use the exercise machines in conformance with the current rules.  The tent is open at the ends but closed at the sides.  In a climate where one can walk, run and cycle on decent paths in much more separation from other people, it's hard to see why people would want to do this, although having one at home is understandable .. 
We are getting high smoke haze from the Creek fire in the Sierra national forest, so the air isn't as clean as it was earlier in the week.