More to the point the team is being hurt by not having a better driver full stop.
Hamilton leaves and Mclaren are crap and their development through the season is rubbish.... Button needing to use Hamilton's set up repeatedly after complaining all year about balance and not being able to get the best out of a car.
When you bring a new wing, and the driver can't dial it in, then you don't know if the new wing is better or worse. When 5 new parts come along and the driver can't dial it in or adjust his style, then you have no idea if that group of parts is wrong.
The team is being hurt, but not by the inexperienced driver, by the experienced driver.
Button was using a top notch driver's set up because he couldn't find it. Hamilton tested new parts, found where they worked and Button copied him.
The lead driver at any team generally does this, the inexperienced driver does not need to and shouldn't remotely be expected to. If button was dialing in the car perfectly Mag could just copy his set up.
Jenson Button, the Theo Walcott of DM's F1 world.