All I can add to the discussion–and I’m going to be really, really, REALLY frank here–was the atmosphere here in NY when this happened. Crime was constant, random, and horribly bad. The subway was filthy and dangerous, with graffiti everywhere that came off on your clothes and was not pretty and artistic at all, dead-eyed young people with loud radios, and usually 2-3 homeless people sprawled at the end of the car. You did not go into most of the parks (except Central; Bryant, Madison, Washington, Union–all were no-go zones. And if you were a gril, you also stayed across the street so you would not get dragged in). You took off all your jewelry before going on the subway or for long walks. You scattered your money about your person except for the 2-5 dollars of mugging money you kept handy, in the hopes the mugger would accept it and go away. Mothers in bad neighborhoods put their children to sleep in bathtubs because stray bullets would not find them there. Times Square was also a no-go zone; as a girl men would routinely expose themselves to you as you walked–quickly, without stopping, head down, coat closed, purse clasped in both arms–to the theater or a restaurant.
Basically, growing up in the 70s and 80s, I was taught that it was a great city but that the criminals were everywhere, pervasive, and that they would always be there, and that every man was a suspect. And sadly, men of color were particularly suspect, and they knew it, and all too many of them, feeling they had nothing to lose or prove, acted it. Loud radios (no earphones back then), loud clothes, loud talking, cursing in front of children and old ladies, lots of attitude, towards everybody, black people, Latino people, white people. I can’t totally blame them, they were so poor and so lost. Nice white New Yorkers like me were told to pity them since they had such bleak lives and no prospects–but, make sure your necklaces are tucked in and your rings off anyway, honey. And the point was, this was normal. These guys were in control. Regular people, of all classes and colors, were told not to fight back, not to make eye contact, keep their heads down, and hope to God that these kids weren’t going to get them this time. And surely, life would never get better. It had gotten worse for years and would always keep getting worse, especially for those of us in the outer boros with long long subway rides and nowhere to escape to. (Thank God we were all so wrong!)
One of those “kids” on the subway had raped a neighbor girl so badly she needed stitches. The screwdrivers were sharpened as weapons. Goetz may not have known this, but these were the sort of people they were. Guys like this spread fear not by waving weapons around, necessarily, but by looming, staring, and making threats that may not sound like threats when you read them on a computer screen in one’s house, but were on a par with a stranger following you out of a club, cornering you in an alley, and leering “Hey baby, gimme a kiss.” Cute when your boyfriend says it at the prom, but…
So when the news broke about what Goetz had done, THAT’S why he became everybody’s hero for a while. Finally, someone had said NO. Not me, not this time, not here. Violence had finally been dealt back out by a mousy little blond guy who was the stereotypical victim. The hunters had finally been taken down.
Now, that changed fairly rapidly IIRC (I was a teenager)–first the racial angle made people uncomfortable, then the paralysis of the unlucky teen, then the fact of the second shot fired into him, then that there were other people nearby, then the fact that Goetz fled…He has a mixed record now, and your perspective will depend on your race, age, sex, and record of being victimized during the bad times. But the OP asked why people at the time initially thought he was a hero, and here’s my perspective. Sorry to be so blunt, but it was a blunt time, with nerves frayed and snarling frustration under everybody’s surface. Goetz’ erupted in a spectacular way and, for a moment, he was a proxy for everyone elses. He was our sheriff.