For 10 years, from right after his parents’ deaths and until his 11th birthday, apparently nobody was nice to Harry, not even outside his home. His abuse was looked over at school and he was always bullied. Even the teachers didn’t seem to do a thing about it. I know Harry was born in 1980, so much of his childhood before Hogwarts was in the 80’s. Still, I have trouble finding something like this believable.
Yet, there were no new students or staff at Harry’s primary school who were horrified. No teacher wanted to help him with his stress or stand up for him when others bullied him. No student wanted to do the same.
Also, most people, especially in an area where Harry lived, don’t see the same people every single day. There would have been lots of visitors, new residents, deliverers, vendors, and many other people not native to Little Whinging or Privet Drive. And it seems that nobody has been appalled by how the Dursleys treated Harry. Not one individual has reacted with, “Oh, that’s terrible! Aw, that poor kid. I wish I could help him. I feel so bad for him.”
Unless there are charms that keep muggles from feeling sorry for Harry, I don’t find something like this too credible. There has to be kinder, empathetic, and even highly-sensitive people in the “Harry Potter” universe. Many muggles would have been upset to hear about how the Dursleys mistreated Harry. They would have felt sorry for him and even disgusted with how Dudley got spoiled. Even if that type of treatment wouldn’t have gotten the Dursleys in trouble with authorities at the time (not just because Dumbledore might have used magic to prevent that since Harry needed to be with a blood relative to stay safe from Voldemort, but also that the laws about child safety were different then, according to my research), Harry would have encountered at least a few muggles who said that they felt terrible for him and showed their sympathy to him. More would have said how sorry they felt for Harry in front of him, whether directly at him or to somebody else. A lot more would have said it out loud, but either not in Harry’s sight or would have thought it in their heads. At least a couple of muggles would have gone to the Dursleys and asked if everything was okay, and if they found out the truth, they would have felt horrible for Harry and showed it.
Lots and lots of people would have also ruminated and obsessed over how Harry got treated by his relatives, day in and day out. They might have even been down about it to others, talked about it a lot, and tried to do something about it, even if they couldn’t.
If the series were truly believable, Harry would have met or heard countless amounts of people who didn’t like how his relatives treated him and said how terrible it must’ve been for him, and how bad they felt for him. Maybe Harry would have even had a kind mentor nearby who wanted to check on him and be nice to him. Even in the 1980’s, before the Internet, the fact that Harry was abused would have made it to others, and a good number of them would have been horrified.