Because in sports there are numerators people involved taking their money from them and positioning them and coaching, assisting, training and everything else for the $$$$. In baccarat they have only themselves and of course the systems sellers and the authors of books that promises millions and easy wins, etc. They have only themselves to forge ahead and they have no real clue, training, experience and knowledge to survive. The complete opposite in sports and music when someone is discovered, etc.
I watched 2 (30's something) people with their accumulated 'life savings' of sorts lose it all over the weekend. The two players had a combined $100k or so and they we going to smack the casino and turn that $100k into $500k or greater. Did not work out that way at all.