^That's just people misremembering because of all the toxic masculinity #metoo stuff that's been in the zeitgeist, and because Steve has become the breakout star of the series. Originally, Jonathan just went around town taking pictures of everyone and everything, and he ended up taking more pictures of Nancy than most, because he was crushing hard on her. He's looking around the woods at that moment, sees her by the window, and looks in the lens to get a better look. Then he can't help himself and starts taking pics because she's kind of looking out the window thoughtfully for a moment, but he turns away when he notices what she's starting to do.
However, all this is misinterpreted by Steve later and he uses it to embarrass him in front of everyone, calling him a perv even though none of his pics are actually pervy, he just has a lot of pics of Nancy when she isn't aware. It's weirdo loser behavior, so Jonathan is too embarrassed to push back and say they're not pervy. But Steve wasn't being a hero, standing up for his girl against some guy who was violating her privacy. People forget that Steve was a douchey teen jock back then, picking on the local weirdo for sport. Jonathan didn't actually do anything wrong, other than being socially awkward.