I have two specific examples of times I have brought in food and the result.
Situation #1 - One day, we decided to eat BBQ at a rib place that in its heyday, was packed. It was very early and quiet. My DS would not eat ribs so we bought McDonalds in. We explained the situation to the person at the podium and told them that if it was a problem, we would be very happy to leave. She assured us it was okay. We sat, ordered drinks and food and all of a sudden the owner came out absolutely incensed that we had brought in food. I calmly explained the situation, offered to leave but was told it was okay.....this once. It was an insurance issue according to the owner. He also told us that the waitperson was in big trouble. We apologized to the waitperson who was very gracious about it. The situation didn't sit well with me and we quickly ate and never returned.
Situation #2 - My husband and I love exotic food and we have been going to a storefront Thai restaurant for close to 15 years. When our son was born, we continued to frequent the restaurant and brought in McDonalds with us every week. The restaurant was trying to build a clientale and they never, ever were anything but gracious about the situation. Within a few years, DS was eating Thai with the best of them and we still frequent the restaurant on a regular basis. It has a thriving business and they continue to be gracious and accomodating to everyone that walks through the door.
Oh....and as for the first place......they're out of business. I certainly don't wonder why.
With the proliferation of restaurants in our area and the amount of times we eat out on a regular basis, we can pick and choose restaurants. And we do on an ongoing basis. I'll always remember and patronize a restaurant that helped me enjoy a meal when it was clear that one tiny member of my family was not interested in eating that sort of cuisine. And when that one small member decided to step up to the plate and taste, it was largely due to the fact that he had seen us eat that sort of cuisine for months. His curiousity got the better of him. And the graciousness displayed at that restaurant of choice has made it a favorite with not only my family, but other families who also have children who have developed a taste for the exotic by watching their family dine on unusual dishes.
Initially the situation doesn't always favor the restaurant but if they work with the patron, they are rewarded with loyalty and appreciation. I know that works for me.....and them.