There is a logic behind that: crotch rockets ride so fast that the tunnel vission impedes seeing anything outside the road. Harley bikes are so slow that only harley rides have the time to notice you are on the shoulder

Don't put all the blame on the ones who didn't stop. I bet you that if you waved them to stop when you saw them, 100% of them would have stopped and give help. Even in this individualistic world, I think that 99.99% of the people wouldn't turn their backs when asked for help. The difference is that today, people either have trouble to recognize when a situation asks for help, or if they do, they just look other way waiting for somebody else to help. "If it was indeed an emergency, he should have let me know"
Last year I left the reading light on in my car for three days. Sure enough, when I tried to start, the battery was flat. I have roadside assistance, but didn't want to wait one hour for it to arrive. What did I do? Wave the first car to stop and asked them if they wouldn't mind to give me a jumpstart with my cables. They gladly did, but their battery was so small that was not powerful enough. I thanked them and waited for the next van to come and did the same. He also helped me, but it turned out that my cables was very thin for the current involved. Finally had to call assistance, but only after two complete strangers helped me.
You must be generous to give help, but you should leave your pride home and ask for help when you need it. Many of us consider ourselves so good, so successful, that we would never admit we need from others. And we disguise it as "roadside assistance", that is, I don't need help, I'm just buying a service like I buy a beer. People is too proud to ask for help, and many times they feel offended when offered help. No wonder that people refuse to offer help unless asked for it.
I have had neighbour's kids sleeping at home when their mother got so sick that his father got to take her to the hospital and stay with her. And I got a neighbour come to sleep at home at 1 in the morning to look after my 2 year-old daughter, and leave her husband and daughter at her own home when my wife started to bleed for a miscarriage and we had to go to emergency room. Still there is some help that no money can buy.