If your recursion is that deep, you're doing something wrong.

I don't think you can (validly) say that. It totally depends on the algorithm. Quite often it depends on the data structure. You may as well say if you have a tree that's more than 100 levels deep, you're doing something wrong. Preposterous.

You would NOT try to fool Perl into letting you go thousands of levels deep.

It's not a matter of "fooling Perl". The deep recursion warning is there to alert you just in case you have a runaway recursion.