It's an interesting view if you have seen Wishes before, or you just don't want to deal with lots of people standing around in a theme park. But the previous poster is correct - especially if you have never seen Wishes, you should know it's meant to be viewed from inside the park.
Besides, the food does come with the show, so if you don't care about the food and are just going for the fireworks there are better and less expensive ways to see them. If you love the food, go for it. I'd bet that most of the people who crowd California Grill for fireworks time have probably seen the show from the park before.