Suicide as a consequence of diagnosed clinical depression is no more "a selfish move" than the fatal stroke that concludes a bout with metastatic cancer.
Ascribing value judgements on people suffering from very personal diseases doesn't help and may actually prevent folks with suicidal ideations from getting help.
If you think that telling a clinically depressed person that what they're thinking about doing is "selfish" is going to "snap them out of it" then I'd recommend you do some soul searching.
Agreed, but this is very different from an objective analysis of why someone killed themselves.