Well, considering that most of the schools don't teach that algorithm... it almost surely wasn't worth learning it.
https://news.ycombinator.com/item?id=25415441
Roman numerals were easy to chisel into stone. Beyond that, kind of a headache.
However what we call regexes today are, often, a considerably more theoretically powerful tool that can match some[1] non-regular languages. Programmers are tempted to use them as a general purpose matcher, which they absolutely are not. Thus, the punchline of the joke.
[1] As far as I know the exact computational power of perlre isn't proved, but it can describe some subset of the context-free languages at the very least.