Yes. It's well known that someone with, say, Down's syndrome may need a full time handler and is extremely unlikely to be a productive member of society (they'd need to be twice as productive, to make up for their handler).
Many couples when informed of Down's risk choose to abort.
We're not talking, in these instances, of someone who is mentally able but with a mobility issue, we are talking about people who will never contribute to society. That's money taken away from you, not some billionaire.
That said -- rounding up people and killing them is insane. But failing to test for birth defects and not working to prevent them is also insane.
Some ways this thread is going are kind of concerning, like, we don't know why people are depressed, so doing something like selecting against people who are liable to be depressed is probably a huge mistake. We could end up with generations that are poorly equipped to solve problems under pressure, etc, or whatever depression may naturally exist to help the host do.
Could caring for these kind of people have a utility in helping us think about compassion, and our values in a more broad way, that enables not making sub optimal decisions in cases that would have negative returns.. To use this thread as an example .. if we were in a society that was black and white utilitarian about one type of disability, it might lead to that thinking being applied directly and 'naturally' to this mental health issue also.
Maybe? But there are cases where the answer is either "no" or "it's too expensive." I've interacted with people with very serious mental disabilities and while it's not necessarily a negative experience you can usually tell the parents are lying to themselves when they say they enjoy their life.
If you create a hypothetical where the outcome is bad then I am not surprised the outcome is bad. You need to find something more concrete. I actually gave one: selecting against something nebulous like depression may have deleterious effects on the human germline leading to our own extinction. There's evidence that depression aids in avoiding potentially deadly stressors and increases problem solving ability.
