Parents involvement is crucial for a kid's success, whether getting A or getting voted. It is also the choice and interest of parents (may be it is indeed fueled by their ego or may be genuine interest).

Kids getting awarded without parents' involvement (or merit based as you say) through public voting is only possible if all candidates are equally exposed and the voters are well-informed about the candidates so that the voters have enough information to make their choice. This is not normally true. Most voters do not look other candidates than the one they are going to vote. This is nothing but a hollow judgement at best. How could the voting result coming from such a hollow judgment be a fair result to evaluate the kid's own merit? That is the limitation of the competition and the limitation for expecting the merit of the award. Whether you vote to please the parent or to please yourself, if your vote helps to win the kid, then the kid is the winner making both you and the parents smile. I think, that is the only purpose of such parental campaigning.