I think if you leave kids/wife/family behind than you would be a coward cause its your responsibility to take care of them. If you're single with no one depending on you than I wouldn't consider them cowards nor brave. No one chooses to be born but taking your own life for some reason remains taboo. I say fuck it do what you want.
A very close friend of mine, actually a training partner of mine when we were younger, killed himself at the age of 41 - I miss him every day! He was a good man, a strong man and an inspiration. He was originally my older brothers mate, but we started training together at the gym as I was still only 19 I was a hard trainer - he was also one of the strongest natural trainers I have ever trained with - he had a higher intensity level than the average human being, perhaps this was also part of his problem. I don't know what happened between the last time I seen him and the time he hung himself in his backyard a few years later - but the story goes that his wife was having an affair, their was a lot of heated arguments and some domestic abuse - my friend had two children. One day he come home early from a business trip and caught his wife fucking a work colleague. A week later he was dead. My friend was a solid citizen with no hints of mental illness. His only real hang up was at the age of 18 discovering he was adopted and that his parents weren't his real parents. Anyway, he hung himself in his backyard so his wife would find him, that bitch then rang her lover to come and cut him down from the tree. They then rang the emergency services. I never liked his wife and always thought she was a bitch! She never even told the police she was having an affair when they investigated, this information only came out at the coroners inquest, she said she didn't think it was relevant. Anyway, I miss my friend, I do not think he is a coward, I am sorry that his personal pain was so overwhelming that he had to check out, and I will always think fondly of him. I must stop, as I am beginning to get emotional.
also just to add, my friend told his closest friend at the time (a policeman of 20 years) that he was going to kill himself - this was not like my friend to speak like that! and he was the type of person who only made verbal things he was actually going to do, he was not a man who was full of hot air, he was a fairly serious guy, anyway, his friend dismissed him and said that he will call in a couple of days, two days later he was dead - so please people, monitor your loved ones closely when they are struggling thorough a hard time, you may just save their life!