I think it was confusing people because pro sports players are often paid by an org or team that will fire them if they don't show up for the endless hours of training. They also get huge amounts of resources to make that training more effective.
Versus, say, a touring rock band that gets a cut of the performance revenue. I don't think there's anyone paying them a multi-year contract salary.
saying training is work is also confusing, because just doing your work is not training either. I'm kinda angry at the school system for never teaching me about dedicated practice. For the longest time, I did believe practicing something was just doing it over and over.