Sometimes functions are not enough.
Calculating a greedy algorithm for an optimization problem, functionally.
Why reason *about* algorithms, when you can reason *with* them?
Will machine learning automate programming out of existence, as it is doing for many other professions?
We accept that data structure determines program structure. But we should not forget that it is not just the input data that may be structured: output data may be structured too, and both may determine program structure.