As the foremost domain expert on the subject (the subject being what I meant by my own comment), I can say with 100% certainty that it was in fact a joke, or rather a poor attempt to paraphrase Mark Twain's: "I didn't have time to write a short letter, so I wrote a long one instead."

Of course you are right, optimization does take time, whether you are optimizing a computer program or a letter.

It is a joke.

Things that are shorter or smaller generally take less time to produce than things that are longer or larger, it's a joke because the opposite is true in this case. Jokes can be true statements as well as falsehoods.