Although I hope the majority of posters are correct, I can understand op's concern.
DS is now 14, according to virtually all his teachers, past and present, he is a pleasant young man, a pleasure to teach, a credit to me, they would love to have a class full of 'ds's name' - but he is disabled with unspecified learning difficulties on top. He struggles academically and no matter how hard he tries he will rarely produce work which is anywhere near that which is expected for his age.
He has always struggled to gain house points, when he was younger he may have managed in a year the same number of house points as many gained in half a term. Now, his school has a website I can log onto and see any rewards or sanctions he has had. Since September he has had one sanction (fair enough, he forgot maths equipment) and no rewards, despite having a really positive parents evening. I suspect the only reason I don't have a school refuser on my hands is because he is a people pleaser at heart and does not like to get into trouble. And no, lack of house points is not the only reason, but when you are working to the very best of your ability and getting into trouble for not producing suitable work, when you see others not seeming to work as hard but getting lots of house points it is extremely demoralising, and when it starts in reception and follows you all the way through school, it isn't surprising that certain children just give up.
Sorry, a bit of a rant I know, but op, I really do understand where you are coming from.