Not everyone understands depression.
Even those who post online claiming to be depressed clearly do not really understand the depths of depression.
We only know what we have experienced. We might think what we feel is terrible ... and it is for us because we have never known anything worse. Some else who has been to darker places might have a different perspective.
I will not explain that. Anyone who has been there will understand why I say it.
Let me ask you, what SHOULD people say to a depressed person who posts their 'I want to kill myself' message?
Why is it their responsibility to do or say anything to help the troubled person?
As you rightly say, the platitudes offered by most people who answer such posts don't help.
Some of us do try to help but it is not always appreciated.
The problem is in the head of the troubled person. It is not a fault with reality. It is a fault of interpretation, of critical thinking, of personal situation and of self management.
I freely admit there are times when critical thinking and self management are about as realistic as walking on the moon, but we have to grasp the times when we CAN get to grips with a our problem and fight back.
No one can do it for us.
WE are ones who need to change.
It is not compulsory. If someone wants to kill themselves, it is not my place to tell them not to.
We all have choices, including the choice to fight back or to not to fight back against what ails us.
I have offered suggestions in the past to people who claim to feel depressed or suicidal - not including any of those empty platitudes but serious hard-core, experience based insights. Most of those answers got reported - by whom I shall never know but certainly by those who don't understand the reality or those who don't like the suggestions.
So, my friend, we have a problem. Only 'safe' answers are acceptable yet they are quite useless.
The censorious nature of members of this site who report frank answers that are intended to be genuinely helpful have the effect of rendering it impotent. Platitudes satisfy the weak minds of those who have never suffocated in the depths of darkness. Those of us who have been there find our answers get reported which is why this is more of a discussion than a helpful answer, reflecting the nature of the question.