Given that a certain newbie was (like) a child, would downvoting necessarily be a (helpful) punishment?
It could be, but it could as well be, like already said, discouraging (newbie leaves and chooses "easier" community instead of learning) or give some sort of defiant pride to the childish newbie about having "upset" "elder" monks and gotten downvoted and had his/her node displayed in the worst nodes section.

Given that the vast majority of newbies are hopefully not childish at all, we should just tell them that votes should not be taken too seriously. (But voting should.) It should also be noted that the majority's vote is not necessarily the right vote. And finally, that the voting system here at Perlmonks is still some kind of indication / information about "good" (informative, new, important) and "bad" (incorrect, ignorant, trollish) content.