Riding sits on a clone is still advantageous. There's a small chance at a huge profit with sits and when using a clone for it, you get a small chance at a huge profit all whilst being able to play mini games, flip trades, or even double riding for sits.
I get that playing mini games against your clone is more advantageous than using a clone for sits but the reasoning staff uses for why you shouldn't be allowed to play against your clone in mini games also works for why you shouldnt be allowed to ride for sits on a clone. It's not like people gain 0% advantage from riding on their clone. If it were so, people wouldn't do it.