Well, "why should I pay for my neighbour's re-education when they should've just picked right in the first place?" - if you are lucky enough to pick a field which grows for the rest of your life, and you're a reasonably good worker, you're never going to take advantage of that and so your neighbour gets more than you from the Government. Not fair! /s
Is that actually a prevalent attitude, though? I mean, it's stupid... someone else retraining is easily still having it harder than someone who "picked right". And in the end, I'd much rather help pay for someone's education than have to walk past them on the street, begging for money.
Sure, except that nobody wants to do that for some abstract reason of "fairness", so the problem needs to be mitigated another way.