This is a SERIOUS question about an admittedly silly facial feature that has just come up at work.
Leaving aside *hilariously* ironic students, I don't know anyone in their right mind who would countenance growing one, so once the last generation of 'caterpillars' shuffle off this mortal coil, that, as they say, should be that.
I can't possibly see it ever coming back into fashion, which would leave us with a tonsorial curiosity to match those really short and really greasy haircuts with the centre parting circa 1890. Yes! Yes?