Unfortunately there are still alot of parents that feel this way. Mine were not thankgoodness.
Many parents, especially Mothers, have the future laid out for their kids already. College, Career, marriage and then Grand Children. Waltons Mountain as I used to call it. Well we all know that Waltons mountain doesn't exist other than TV fiction. That model family next door today now has its sheletons exposed. Divorce, teen pregnancy, alcohol or drug abuse, eating disorders, infidelity, the works. But homosexuality? OMG! It may have been fine that uncle Roger was a "confirmed bachelor" but not MY child!
Parents of course want what is best for their kids. They don't want to see hardship for them. nor violence or disease. And to many parents that is what they think we are doomed to. Granted they are right in some cases. Well, not doomed to, but exposed to.
Things may have gotten 200% better since 1963 for gay people, but I still don't see many that are 100% out to family, friends and coworkers. Maybe 99%, but there are still people out there you don't want knowing.
Parents usually come around after the shock wears off. After all, unconditional love is just that right?