I have always wonder how come Kimmy did not have a boyfriend until later Season of Full House.

Nobody wanted her probably.

I wonder why no one would want Kimmy

When i was in high school, back in the day, dating was about popularity, and she just doesn't seem like she'd be that popular with boys. Though she was in some typical classes, we don't even known how many; she might have been in some sort of English or science or something for slow learners once high school started. And, unfortunately, there's a stigma attached, or was back when I was in school, that would keep the slow learners from getting dates.

Some boys did want a girl who was all looks, and little brains, but those were the kind of boys D.J. probably helped Kimmy stay away from, becuase there were no doubt some boys who would really have taken advatnage of a girl like her.

So, I would guess that popularity, stigma, and D.J. perhaps beinga bit protective, would be the reasons.