Nowhere am I refuting any of that, at all.
I was making a point of the blanket 'anyone who has mental health issues shouldn't be allowed in relationships' and how it's a problematic way to think.
Well it was obviously throwaway hyperbole. No need to go all SJW. Given the number of people that experience some kind of mental health issue during their lives, we've probably all been in a relationship with it and maybe been able to work through those problems to a better place.
That's quite different from those people we all know who simply suck the joy out of life and destroy relationships and the people around them because they have mental health issues that they are unwilling or unable to overcome.
People will often stay with a partner out of loyalty, and it takes them years to realise they are in an abusive relationship, or that they can't fix someone. Two lives wrecked instead of one, more if there are kids involved. Given how poorly most people understand others, let alone themselves, it's no surprise.
So while I agree we shouldn't stigmatise those with mental health issues, neither should we stigmatise those that can't or don't want to put up with the drama that such a person can bring.
If one day the likes of mental health issues are really treated as a normal part of life, then it should be just as valid for someone to not wish to deal with that, the same way you might not want to date someone who has kids, is in a wheelchair, has no money, etc. Once mental health issues are normalised, they are just like any other thing we may or may not want in a partner.