I think with something like suicide you are dealing with something so intricate - basically the workings of an individual mind who has experienced life differently from anyone else.
It is impossible for others to get inside that person’s head and think of mitigating factors as we are simply not them nor ever could be.
That said, it is understandable for others to point them out.
That is what makes depression so difficult to ‘treat’. Every case is different yet a lot of people don’t seem to get that.