I think Terry Pratchett would probably be laughing uproariously.

Oh, it’s fine, the brain is a different kind of fat! /s

But just waiting for others to die out doesn’t always work. Take for instance the southern US. It took the federal government intervening (sometimes violently) to actually deal with a lot of the ingrained racism. And even then, there is still plenty around, and in some places it is gaining in popularity. In my mind, the argument you are posing could easily be subbed in as "we shouldn’t allow mixed race couples to have children, as those that are racist will inevitably traumatize the children. " I get that your argument is probably not from a place off outright homophobia, but it is kinda homophobic in that it accepts that children shouldn’t be around gay/lesbian parents because of what others will think and do. Is Poland shitty to LGBTQ couples? Probably, but just waiting for people to eventually accept them isn’t gonna fix the issue.