In your experience. Not to be flippant, but if you are developing software in an environment that has lots of changing requirements, there are ways to write that code and developers who are good in those situations.
Similarly, there are environments where static requirements are cornerstone for success. Certain methodologies deal with this environment better than others and certain developers will be more successful than others in these environments.
Above a certain threshold, yes. But I have seen so much utterly crazy hacked-together crap, which was clearly not caused by changing requirements, but rather either incompetence or negligence. I'm guessing that so have you.
Similarly, there are environments where static requirements are cornerstone for success. Certain methodologies deal with this environment better than others and certain developers will be more successful than others in these environments.