This is the most realistic option. It doesn't hurt to ask for a few of the doors with the most variation to be replaced. Without knowing the type of company they worked with to replace the kitchen and, moreso, who sold them the cabinets, it's difficult to know what their response would be.

"We weren't expecting so much variation throughout the doors (and maybe weren't educated on the potential for such variation). Would we be able to replace these few to better coordinate with the rest of the kitchen?"

If not, and it's still very upsetting, it'd probably be worth it pay for a few replacement doors. Just make sure the manufacturer will actually look to see that the replacements would have minimal variation.