This does seem to be a chicken and the egg problem. Which came first: literary critics ignoring science fiction or science fiction ignoring literary critics? As Gordon Dickinson said in Dorsai!, "I respect those people's opinions whose opinions I respect." Or perhaps you prefer the more poignant Piers Anthony version in Xanth, "Worthless people's opinion are worthless."
I think the science fiction readers and the literary critics have a mutual appreciation of ignoring the other.
The snobbery and the hubris of literature is best represented by William Shakespeare. Harold Bloom went on PBS with Charlie Rose and exclaimed that Shakespeare was the most moral person ever. He also said the bard was the most prophetic about human nature, the future of mankind will always be predicted by Shakespeare. So there you have it. Shakespeare has the 411, has the goods, on human nature. Science fiction is an affront speculating on human nature to literary critic sensibilities fixed on William Shakespeare being the end all be all. The likes of Harold Bloom look down on those of us who exclaim, "Everything I learned about life I learned from Star Trek."
Literature is just William Shakespeare worship.
As for me? I found Shakespeare to be morally bankrupt and human nature decrepit. The world is not a broken record on some endless skipping loop, which is the sum total of all of Shakespeare wisdom.
My own personal credo comes from Frank Herbert's, "The God Makers":
Which is better?
A good eye,
A good neighbor,
A good wife,
Or the understanding of consequences?
It is none of these. But rather being a warm and sensitive person that understands the price of individual dignity and the worth of human fellowship. This is best.