A decade ago my brother and I discovered Chin's Asia Fresh. At first it was just another Chinese restaurant that kept our parents happy because they didn't use MSG. But as the years went by we moved away it became one of a few places that my brother and I would return to whenever we visited home. This became tradition, and was strangely one of the things I looked forward to when returning to Minnesota.
At some point Chin's was bought out, and bit by bit started changing, but it wasn't until the menu got swapped out that we suddenly lost interest. The taste of our favorite dish was key. I feel this way for a handful of other restaurants, but the list is tiny. For many others it's the atmosphere or connivence or people or price that brings me back. So many different reasons to prefer a restaurant must make it hard to change, because changing anything will annoy at least some people, but at the same time there might be a need that isn't being satisfied by the current experience.