DP broke his leg badly when he was 6, so around 1983 - his mum walked five miles a day after dropping his little sister off with a friend to visit him during the day, leaving at lunchtime. His Dad would visit on the way home from work and his grandparents would visit at the weekend. He was in hospital for about three months and says he loved the hospital school.
My mother didn't visit my eldest brother for over a week after he had his tonsils out - because he turned 12 whilst he was in, he was moved onto the adult ward, which was full of very elderly men. He only ever saw a doctor once for the next 50 years because he refused point blank to have anything to do with them afterwards. And then she wouldn't visit him or call when he was in hospital dying. I am told that she got wheeled down to see me when I was a few days old and in SCBU but she didn't go back again until I was ready to go home; my father called in some favours because he was hospital staff to be let in during the day sometimes, but that was purely dependent upon a friend of a friend being in charge.
I've also seen a boyfriend's sister decide that as she was sure her 32-weeker preemie was going to be fine, she was going to go home and come back 'in a couple of days'. They finally got around to it at the weekend when the weekend shift staff came back on from the previous week and phoned to find out where the fuck she had got to, as she'd told them she was just going home for a shower and change of clothes not to crack open the Stella and roll a shitload of joints for seven days.
I can see why a baby or small child might have to be transported urgently and the Mum being too unwell or there not being time to sort out transport for both, or where somebody is a lone parent of several children and can't be there all of the time, but to just not turn up at all when it wasn't impossible, not even for a short visit, feels so cold.