There are serious questions regarding its legitimacy.
And that is a death knell for competitive sport.
You're mistaken there, I believe. If you replaced 'high priced professional' for 'competitive' I might be inclined to hope you're right, but there are a multitude of competitive sports where true athletism occurs. Who needs overpaid primadonnas at outrageous prices when there are so many different, and cheap, alternatives. You like racing? BMX starts at 5 years old, and by their mid-teens they'll either have loved it, or left it. High School sports? Awesome competing! Street hockey? Paintball? Girls softball? Winter sports? Water sports? The list is endless and each are rewarding and gratifying. My nickel's worth ...
No, there aren't "serious" questions regarding its legitimacy. Questions? Perhaps, but not "serious" questions by "serious" people.