Strictly speaking as someone who has both lost an immediate family member to suicide and has had suicide attempts herself, it is easy to view it in terms of selfishness. Generally when we speak of suicide, we are not referring to 'honourable deaths' where someone willingly gives their life in order to cause immediate change for good, like pushing someone out of the way of a train and getting hit themselves, or whatever hero-death situation is present in many Hollywood movies. When we talk of suicide, we're referring to the gritty path of self-inflicted gunshots and what not - an end to whatever has caused their mental state to deteriorate.
When my father killed himself, I instantly viewed it as selfish - after all, he was my dad. I'm hardly going to chastise myself for reacting as any immediately bereaved child would act in such a situation. When you view suicide in terms of causing pain to other people, it is very easy to categorise the act as selfish, dismissive. Why would a person willingly cause harm to others, the ones they love, and put their own hurt over anything else? It's very easy to come to that conclusion and I do not blame those who do - it's a pretty common emotional response due to not framing the idea of suicide correctly. However, assigning emotional terms to suicide puts the onus on the people affected and not where the onus should be, the person who died.
My breakthrough in understanding has been through my own trials in regards to mental health. One certainly does not need such events in order to understand the situation more clearly, but that's what helped me. People with suicidal idealation do recognise the impact it may have, it's a bit dismissive of the intellectual capabilities of the person involved to say that they don't do so. We recognise how it will damage others, we're hardly emotionally void. More often than not the mere fact that we are considering the people around us has saved the lives or at least prolonged the lives of those considering suicide. Likewise, I think it's dismissive to view uniformly view suicide as a form of escapism. Escapism implies there is somewhere to go. Many suicides are the person escaping from their mental health or an outside situation, but is it really escaping when you are not jumping so much as being pushed? My point is that it is a bit cruel to paint such a complicated social transgression (which is kind of what it is once the act is over) with general terms.
Suicide is only selfish when you are considering yourself and other people over the person who actually died.
At the very least, what do people think of medically-assisted suicide, such as in cases where patients have a terminal illness and/or are in chronic, debilitating pain? Is that "selfish," and does it matter?
There is no reason to oppose it other than imposing one's ideology on people who at that point would rather die as 'themselves' than what they will likely become. At any rate, the people making the decision will be of a sound mind, or will have people acting on their behalf due to a decision made when they had a sound mind. That is generally something not afforded to the majority of people considering death. The only reservation I have about the subject is not the act of medically-assisted death itself, but those in charge of administering, particularly when it comes to the elderly. I fear that there may be situations where the old and infirm are taken advantage of. But those fears are not enough to dissuade me from my original statement.