It's very hard to judge this from the outside, because a lot of the info is third hand.
We've heard a couple of stories from parents about the seemingly stupid little things that have seen their offspring fall foul of NuHope, and if true, then it would appear that either the system is flawed, or it is being implemented badly.
However, from my own experience as a child, and having dealt with children via voluntary youth services, I strongly suspect that the version of events being relayed to the forum (via parents, via their kids), isn't the whole truth. When I was a child, when I got in trouble, unless it was so bad that school phoned home, the version I told my Mum was always significantly watered down. So, someone on here has reported that a child was given a NuHope detention for staring out of the windows. Probably true, but I would imagine that what little Johnny forgot to mention to mum, was that he spent the entire lesson staring out of the window, thus he did no work, and couldn't answer questions when called upon because of it, etc. The child who was given NuHope for being late to class, because the previous class let them out late - why was she the only one to get a NuHope, surely the entire class of 20+ kids got one? No, just her? I would imagine then that there were other factors at work that contributed to her lateness.
The principle of NuHope seems sound to me, clamp down on the small problems and the large ones take care of themselves. For me, the issue is whether it's being implemented properly, fairly and with enough common sense - and I suspect that it is.
But, if you truly believe that NuHope is unfairly impacting upon your children's welfare then follow the advice already laid out here, and make formal complaints.