Yes, I recall when Disney made this change. I cancelled our MKC Gold card initially puchased with the application provided with the annual report when, as you note, my wife got a free one from her employer. And they are often very rigid/limited in the discounts/plans they offer. As you say, it seems the average percentage amount discounted was only 10%.

Yet the discount with the card, regular or Gold, in any case can add up for several children (and adults) over several days. You also get a discount (~10%) on lodging and some food.

We saved quite a bit two years ago with the family over 4 days/nights at EuroDisney, now more correctly called Disneyland Paris, I believe.

Sometimes Amex also runs some specials with them as well.

BTW- We all did like the Paris location despite some lukewarm reviews etc!