dolly milk
I just don't understand how anyone can say that it's selfish, if it isn't done with the intent of hurting others.
That's like saying it's selfish to buy yourself lunch, instead of just giving it to a starving homeless person.
Intending to hurt others is not the definition of selfishness.
Selfishness is just trying to do things for your own benefit. I can eat the last slice of pizza because it's tasty, and that's selfish. Am I a bad person for eating the last slice of pizza? Not necessarily. Maybe if I am supposed to be sharing the pizza with somebody else and I've had more than my fair share, then eating the last slice would be a bad thing.
Colloquially, however, many people do associate selfishness with taking things and preventing someone else from having them. When people say "That's so selfish," they mean "You're doing something for yourself and ignoring what someone else needs."
In both ways, suicide can be counted as selfish. Suicide is most often, in developed nations, a reaction to difficulties faced in life. For those experiencing emotional pain, it's a step taken in an effort to end your own misery. And while doing something to ease or end your pain is not inherently bad, it's hard not to know that your choice will negatively impact somebody else.
Now, when people use the word selfish to say that somebody is intending to hurt somebody else (which is even farther along the spectrum than the normal colloquial usage), then that is unlikely to factor into the majority of suicide attempts. Relatively few people who want to end their life are thinking "I want my mom to cry for MONTHS! And my sister, I hope she becomes suicidal too! Hahaha! If I plan this right, my dad will find my corpse and he'll be too traumatized to even look at that room in our house again! This is great!"
In fact, I'd wager the majority of suicides in developed nations are committed by people in emotional distress, which means they aren't necessarily "in their right mind" and so perhaps you cannot truly ascribe malicious selfishness to what they do, since they aren't thinking straight.