Perl isn't dead, I use it every day for important stuff. But it is true, people younger than say 32 are not very likely to know Perl well, most of them prefer python
That's what "dead" in casual discussion means though.
Because in the stricter sense that "someone, somewhere is using it", even SNOBOL is not dead.
Are you suggesting that when Mats created Ruby, he was thinking to himself, "I can't wait for the all the first graders to grow up and use my language?"
I rather think that the creators of computer languages think in terms of present, rather than future computer programmers, and not in terms of "My language will make all the Beliebers want to become software engineers."