Do you think one can leave a baby in the car and not be a bad parent?

How can you have 4 people in a car and not even one notices the baby is back there in the car seat? I think they did it deliberately. It wasn’t a big issue when I was young but I did pull a toddler out of a hot car one afternoon and just about whipped the mother. She came to visit, we knew she was unbalanced & she loved to sit around & talk which was mostly BS lies. Sometimes she’d leave the boy with other people but this day she left him in the car. I heard a car horn honking and looked out the door and didn’t see any other car beside hers...thought someone had driven up and drove off. Then a couple minutes later I heard it again. I went to the car and there he was on the driver’s side floor sweating & with sand & pieces of cigarette tobacco sticking all over his face and arms. He had been trying to pull himself up by the steering wheel. I picked him up & he was crying & smelled like pee & sweat. By this time the mother & my aunt came out and saw me & I lit into that mother & told her if I ever saw her do such a thing again I’d whip her. She was shaking and almost twice as big as me, I was 14 at the time.