Calling people cowards for killing themselves is just complete bollocks, that is derived from people's irrational fear of death and their religious/cultural bias. Or, perhaps they don't want to see any of their loved ones go "prematurely". Not being able to ever let go, can in so many cases I've seen be a far more selfish attitude than suicide can ever be. If someone close to you suffer greatly with a non-treatable condition, physically or mentally, without you ever being able to let them pass away as they have requested, makes you the only coward.
From my perspective, killing yourself is probably the bravest thing you can ever do, especially if done with a rational and thought-out approach. Facing the unknown, e.g., facing the potential of non-existence, heaven, hell, reincarnation, end of simulation et cetera. Also, people often neglect to consider the very strong self-preservation instinct which even most suicidal people have. It's not that simple to overcome, which is one of the several reasons why so many with suicidal thoughts may try to avoid suicide by reaching out directly or discreetly unconsciously.
Personally, I'm both terrified and slightly excited at the notion of eventually facing the end. But, in the end it's always going to be something I'll have to inevitably face. If it happens sooner by mine own hand, so what? Of course, I would still never encourage anyone to commit suicide. But too many are left without any other alternative.