I know that Perl is a swiss army chainsaw. Therefore I don't have to remember where that blade originally was to be found because it is part of Perl. Besides, on any machine where I've resided for a while, I know that Perl is there. I don't know that the rest of the Unix toolset is.

In fact until you pointed out that it exists, I'd never looked for a tr utility. Now that I have, I know where another Perl operator came from, and I'll blissfully forget about the tr utility. Its existence is one more thing that I can forget.

YMMV, and in this case it probably does.

Cheers,
Ben