"I believe that what you say is the undisputed truth, but...
"Sladuuch:"
Please understand your parents and how they view the world.
They must have been brought up in public education or accepted the philosophy of it, which is generally an old concept called Nihilism, reconstitued to the "New" century.
They believe that if you assert that "something" is "better" than another thing; you are showing a "discrimination" towards that "something" and against the "another thing." By the logic that they have been indoctrinated with you therefor have commited an act of mental bigotry! {Disregard that they have also made judgement themselves about you and your decision}
The rationale, if it can be called that goes like this:
To use logic, to weigh in your mind, right and wrong, good and bad, etc.
is what mankind has done throughout human history. And look at what his value system has brought about by -Religious beliefs, Government and National Identity, Philosophies, and so forth. The result has been the continual striving, dissention and conflict through the years which has led to fighting/ War/ death and famine/ poverty/ crime and finally ends in injustice.
This is, by the way an inductive reasoning -the conclusion of which is never certain, but can only be assumed.
So, here you Sladuuch, a "reductio ad absurdum;" your parents will reflexively
go to the critical thought pattern in which they will maintain "faith"
in their system, and that no other, indeed any rational agument you may render will be dismissed as by definition, bigoted, "hatefull," and not fitting into non or indiscrimination of thought that has led the human race to this point in history. Remember, to them, objective morality does not exist, that no action is logically preferable to another.
An old "Beatle" song told this, just after the "lads from Liverpool" changed from "She Loves Me, Yea, Yea" to "Imangine all the People." They had traveled to India, visited the Guru, were inlightened, and returned to the USA among other nations to spread the word.
I'm describing this because you most likely will not be able to convince your parents of any logical thought on this matter or others either that require analysis and judgement to be made. Don't frustrate yourself to death, but realize the mindset that has taken over here.