Riding a Bike? Not Going to Happen This Year

We have tried multiple times over the past 5 years to get our ten year old son with SPD riding a two wheel bike. He was fine with a tricycle when he was little, but he doesn't have a good sense of where his body is in space, so the feeling of getting wobbly on a 2 wheel bike was not enjoyable. 

We tried a glider bike, training wheels, running beside him while holding his bike, and just letting him go for it. One year, we went out every day for two weeks to practice without training wheels, but it was so stressful for both of us, we gave up. 

The last time we tried was when he was nine. Sometimes he'll do things for my husband that he won't do for me, so they tried when I was gone. It lasted for about 10 feet until the pedal scraped his leg, and he got off and went inside. When I asked him how it felt later that night, he said it felt like he was going to fall off 100 times in those ten feet, and he hated it. 

There aren't many kids out on bikes in our neighborhood, so there isn't any motivation for him to learn. We decided it wasn't the skill we wanted to push with him, and let it drop.

Is riding a bike a necessary childhood skill? Will it be like crawling where if you don't do it, you miss out on coordination skills? I hope not, because there is no bike riding going on this year!