I don’t follow. Unless I’ve misunderstood, the issue is that Labour decided that better off (generally speaking) parents who pay for private schooling, for lots of reasons, should pay 20% more for doing so. So those parents are unhappy.
But now other parents - a substantial number of which are Labour voters - who bought into pricey catchments for access to good state schools may find they’ve wasted their money and have their hopes for their children’s education thwarted.
So posters who suffered under the VAT change are laughing at left-wing parents who tried to or were planning to game the system they support and urge on everyone else, and who will be distraught at the thought of a shitty school for their children.
No-one’s picking on children (apart from Labour). They’re scoffing at the left-wing hypocrites.
But, as I say, I may have misunderstood.