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. This is what you expect from most teams, senior or better driver gets the car set up better and the less experienced or less good driver takes the other drivers advice on board and learns to be able to do the same. To even hint that Mag's lack of experience in set up would be hurting the team is ridiculous and is the kind of sly comment Button usually comes up with. Yes if Hamilton was there getting the set up bang on, making the car faster and Button copied him Button would be faster... but that is Button's deficiency not Magnussen. he's now the senior driver and should be the guy leading and helping Mag with set up, to bring up his inexperience is to overlook that it's simply Button not being good enough.
It's the excuse making, underhanded crap that Button has come up with for years.