on't you hate it when people state the "truth" when the "truth" is actually an unfounded, ignorant stereotype of a specific subject, place, or idea?

Such as, I was read about the cause of homosexuality... (A friend of mine and I had a conversation. I was trying to inform him that people are born gay, since evolution is determined by well, evolving and advancing as a species while homosexual acts don't occur naturally according to evolution, then homosexuality must be a birth defect since it goes against the norm's (or against the grain so to speak) of evolutionary standards and in no way assists the evolutionary chain of procreation.)
A man had claimed that it was a political party and all they want is equal rights and he was stating the truth.
Ive noticed this quite a bit when someone states illogical or idiotic comments and always claims that it's the truth instead of stating that it's an opinion based on unfounded knowledge... Why is this?

Would be pretty funny if one day a priest walked up to you and said, "You must praise god, for I have a 'very good, generalized idea based on unfounded knowledge, but within my belief system, I generally believe in the higher power and would like you to believe in him too.'" instead of saying, "You must praise god, I speak the truth"

i've had this debate elsewhere - an item has to be 1) well-defined and 2) quantifiable, otherwise a statement cannot even be classified as true or not

e.g. the statement "the sunflower is 3ft. tall" can be tested and turn out to be true or false
on the other hand, "the sunflower is short" can only be tested if there is an agreed definition of what "short" means in relation to sunflowers
and on the third hand, in order to evaluate the statement "the gremlin is short", one would have to identify first what a gremlin is, and how it can be measured in order to classify its size

I can't handle the truth, so I became a scientist because the truth in science is fortunately transient in nature.

For anyone unable to follow marnixR's argumentation, the discussion he has had elsewhere actually related to proof, which whilst rhyming with truth is a subtly different concept. A statement can be true, even though we cannot prove it. And the fact that marnixR does not realise this distinction, coupled with the patent nonsense in his opening sentence, only enhances the truth value of what I told him in that other discussion.

To address the o/p's question; people use words they cannot define in contexts they do not understand to explain concepts they cannot comprehend. Are you genuinely surprised by this or can we interpret your excellent example in your opening post as being a defense of this tactic?