I’ll actually make a case against this workflow, which has lead to cowboy coding and lost knowledge. Yes, it can get a bug fix right away, but if the developer needs to try out stuff until it works, there’s another problem to deal with.
As for logic, this is the place where unit tests will get you to the right place. Writing a test that will do the validation for you does the same as this workflow and stays for posterity, adding the test to an ever-growing base.
As for visual changes, CSS does not need the stack to be reloaded, and markup may not be tied to PHP, depending on the complexity of the app, but I do see the value in that point, where our workflow still has the downside of trial-and-error approach.