I believe he meant no advantage to you. Racers want their bikes as light as possible and are given parts by manufacturers,so as long as it saves weight,they don't care beyond the part lasting the day. Racers also ride all day long,so they want a close-ratio drivetrain with small gaps between gears so they can keep a more constant cadence and save energy. If you're riding 20 miles one way on a MUP,a close-ratio 10spd setup will be advantageous. If you're riding around a city,all it's going to do for you is make you shift more often and replace worn out parts quicker.

There is a big push to 10 and 11spd drivetrains by manufacturers because they think users want the best in terms of performance,and because they can sell more consumables(chains,cassettes). I've commuted on 8,9,and 10spd,and hate 10spd for making me tap my shifter like it was a maraca and burn through chains in less than a year.