I don't think anyone is complaining about the Bens of this world getting the rewards.
What they are saying is that there is a forgotten middle. This forgotten middle can just be overlooked the whole time.
They're then left in the chasm of "I can never match up to the 'good' ones" and "I don't behave like that."
As I said earlier, my dd1 and her friends had a serious conversation in year 1 about whether it was worth being naughty to get a reward. That's how seriously the dc take it, and we do them no favours by assuming they don't notice.
That's not saying they mind that Ben gets it for not pushing anyone all day, but what they do mind is that it doesn't seem to be recognised when they do their best.
Yes, teachers are normal people, and won't always see that extra effort, but it does effect the children who feel they can never do enough.
Perhaps the teacher should, once a week just stop and look at the children going out of the door and ask themselves. Why do they have no stickers? Was there nothing they did today that could have been rewarded? And if they can't actually think of anything the child did good or bad, look for something good the next day. A simple "oh, you've worked hard/looked after your friend/sat beautifully on the mat," and a sticker would just make the difference to how they feel about it, and would take very little time.
I have 3 dc. They're fairly even academically, but their behaviour is very different.
DD1: very keen to always work hard, will redo her work if she isn't happy with the standard, always happy to help, and will often do things without being asked, and would always put herself forward.
DD2: (who also has a physical disability) does her work without being asked, but at times just enough to get away with it. Will help if asked, but tends not to put herself forward.
Ds: Currently being assessed for ASD and ADHD. Works only when has to, can be a smart alec and is the one I dread a phone call from school. Would only put himself forward for anything if it got him out of school work.
At primary level dd1 and ds got the stickers and the rewards and chosen to do things-despite ds hating stickers, they still came.
DD2 was the one that I'd end up drop a note into the teacher on the penultimate week of year saying that she hadn't had a reward all year (on the ones which were very clearly everyone got). Half the time I'd get a note back saying that "of course she had". She hadn't.
Actually she found it very demoralising, and the other two did not find it especially motivating. I think part of her "just doing enough to get by" is that when she did put in a huge amount of effort, the teachers never showed that they noticed.
Ds's behaviour and attitude improved about year 5, and the rewards then stopped.
He commented one time "I'm not good enough to get them for being good, and I'm not bad enough to get them for not being as bad".
I don't think it bothers him especially, but there are a lot of children it does bother, especially in the yearly years.