You don't go there for the food. Eating there is the only way to get in to see the incredible art that's on their property. And the Fondation Maeght is a don't-miss.
I agree it is very pleasant to eat on the terrace. They cater to tourists and I suspect they would fix you a peanut butter sandwich if you asked. The food can be good but not great but I'll always go back.
If you are going in warm weather, it's lovely to sit outside. And you can see some great sculpture around the pool. Also, Fondation Maeght museum is just up the hill (the museum closes midday.)
First time in this area, just looking for good atmosphere and good food. The art is a bonus not main reason. We will be going this summer. Thanks for reply