These are all known mental health issues, with physiological markers, but ultimately they are aspects of human mentality that are present in everyone.
So, to ignore these, and ignore the myriad other mental and environmental issues, and suggest that 'just do it' is actionable advice goes against the grain of much that is valuable in Bhuddism: namely mindfulness and the purposes of meditation. Essentially, it is telling people to achieve presence through force of will, instead of using insight to accommodate their mental situation: only the unencumbered can succeed.
Is anyone saying "stop being such a crybaby" is the solution for all problems? No way. And certainly not the Buddhist way.
Returning to your points on PTSD, schizophrenia, BPD and ADDHD, I can state quite positively that I've read no Buddhist texts so far that discuss these disorders, let alone prescribe Buddhism as the cure. So again, we are more in agreement than not, unless of course you believe that all fear, discouragement and depression amount to PTSD, schizophrenia, BPD and ADDHD (in which case I would have to level the round trip fallacy charge at you!).
However, personally I believe modern medicine is far from understanding properly any of these disorders, and the treatment for them - mainly drugs - is an unhappy one even if that's all we have.
At the same time I also believe that there is a tendency to find the quick fix (what better than a drug) or a solution outside of ourselves (psychotherapy). Not every condition requires this sort of intervention, but there is a very strong trend and tendency to provide it and that's a pity.
What are loving kindness, compassion, joy, and equanimity if not emotion?
As you have correctly stated, Buddhism is not about escaping from life but meeting it head on. I don't think I've said anything that would suggest I'm for escaping.
Yes going beyond the everyday meaning of the words we use, I agree with you fully. I'm just a beginner on the path, full of the fabrications and paradoxes we all live with, and I'm really looking forward to having them all blown away, or more likely - dissolved - as I dive deeper into it. Ah, aspiration!