I pointed it out to be lighthearted, but it's true not sarcasm, and not only true, it's also meaningfully instructive to think about the benefits of lazy evaluation.

For example, a priority queue (list of tasks) does not need to be fully sorted, only sorted to the extent that the highest priorty item is quickly determinable, and there are algorithms and data structures designed for this behavior.

Sorting (other than to print a sorted list) doesn't pay for itself till you do a number of searches, and associative memory hashes are frequently better if you simply wish to find exact matches again. Even the lowly bubble sort has the not-insignificant benefit of finding the first value in O(n) time which may be the behavior you need: lazy evaluation can be the exact right way to go if you are instructed to sort, as you await more info as to what the appropriate technique might be.

I think humor is only funny when it's based on truthiness.

Yes, they are being sarcastic. The list has to be fully materialized and iterated over. Further, the Haskell version probably doesn't have a concept of doing work in memory-sized batches with spill-to-disk, so the runtime would likely be much higher. Of course, I don't know enough Haskell so it's entirely possible they somehow figured this how to iterate over the input data in sorted order efficiently without materializing it.