Salaries might be set per position per restaurant, but go have a look at the staff at your local high-end steak place. Then go visit your local Chile's/Applebees/Fast Casual Dining place.
Which has a more attractive staff? Which do you suppose makes more in tips? (Or would in salary if straight salaried?)
I believe that in a straight salary system that more attractive people would be well served (no pun intended) to seek jobs at higher-end restaurants; I believe that's already happened to some extent. One table turn could tip $100 or more at a high-end place today. That will be partially shared with the multiple staff serving the table, but it's still going to be a very strong hourly rate.