My opinion is a bit different.
"Within reason", I will do what I can to ensure that Ellie enjoys her food. Eating should be an enjoyable part of a dog's day. What if we had to eat something that we didn't really like 3 times a day everyday?
With one little Yorkie, I would give in and get a balanced recipe from a nutritionist or find something she likes and mix it in her kibble. Now if it gets to the point where she constantly wants different foods and won't even eat homecooked, then it would be time to get tough... I'm allfor spoiling these pups though.
If I had a larger dog I would probably mix something that was appetizing to him/her in the kibble and then get tough...