Prejudiced Against Science Fiction?

I've often asked myself why certain people are so prejudiced against science fiction. Here are a few of the reasons I've come up with:

1) They've read some really bad SF.
2) They've read some really good SF, but couldn't get into it because it had too much technical jargon, way-out theories, or high-faluting vocabulary. ( I could name a few examples, but I'll refrain! )
3) They presume SF will be boring.
4) They consider all SF to be along the lines of "Star Wars" ( which is really space opera, not SF. )
5) They've read only SF that is outdated, the ones reality has already far surpassed.
6) They haven't yet discovered that one book that would really, truly appeal to them.

I've read a great deal of science fiction over the years, as well as related genres. Do I enjoy all of it? Frankly, no. But since I write mainly in the field of SF, I need to be aware, at least somewhat, of what other authors have done. But that doesn't mean I consider all equally good or to my tastes.

Once in a while I find something that I really admire, something that speaks to me. For instance, long ago I fell in love with the work of Zenna Henderson. Her " People" stories perfectly suit my tastes; they have humor, emotion, characters I could easily identify with, warmth, and a great sense of place ( the southwest ).

And much more recently I've, oddly enough, acquired a taste for urban fantasy, such as Tanya Huff's "Blood" books, Charlaine Harris' Sookie Stackhouse books, and Cassandra Clare's Mortal Instruments books. A bit of an odd combination, eh?

Any suggestions about converting those who purport to "hate" SF?

MRTighe