It's unprofessional to have a relationship with your boss
Jane's boss wants to know if she will go out with him for steak.
Jane needs to have dinner.
Jane declines and goes home for dinner.
Jane goes out to dinner with her boss.
Their coworkers are glad because if Jane and the boss were dating they are concerned they would not be treated fairly.
Their coworkers do not trust that their boss will be fair with them compared to Jane.