I agree that it should be used sparingly. But for more than 5 years I've wished I had a computed column feature because you are often thrown into code bases that need refactoring and refactoring 100% in 1 commit is not always the safest way to go. Sometimes you want to migrate a codebase in several steps. Computed/virtual columns are an absolutely fantastic feature and it allows refactoring and migrations at your own pace, or as a fallback.