His comment is not without merit. Your view assumes that a high percentage of employees are inclined to donate. Perhaps they are not. If only 10% of employees partake then that's a far smaller amount going to charity.

What would be best is to say "Apple will donate $10k to the charity of every employee's choice and we encourage our employees to add to those donations as well". Then you get a donation even for those who won't donate of their own accord, they still pick the charities, and those who wish to donate still have the chance to do so as well for personal reasons.

I'm just playing devil's advocate here but if you're looking for guaranteed highest donations generated that would be it. Not that I've ever seen any company do that so it's mostly a mute point.