I can only speak for myself, and as such I ask you take these meanderings with a grain of salt. But for me, suicide does carry elements of both cowardice and of courage.
As a species, we know the world is fraught with violence and pain; our neurochemical systems have adapted along with these pressures. Yes, there are some individuals who live in a kind of perpetual la-la land manufactured by market driven hyper-saturated environments. For these folks, and I'm referring to people who live in post-industrial nations where the standard of living far exceeds what was available 100 to 150 years ago, the world presented seems calm, organized, advanced in its laws and social mores. But that is just a very well layered patina that obfuscates the atrocities constantly plaguing the planet. The world, the one beyond the pretty neon colored signs, there exists much chaos and pain.
My cowardice is that I know longer feel able to subsist in the dual reality described above. I just don't wish to face those challenges anymore. In essence, I don't possess the courage to take on an increasingly insignificant existence.
As for courage, for me it begins with the realization that I've abandoned any hope of digging myself out of the hole I'm in. That's a form of acceptance, and it's acceptance that will eventually allow me to transition out of this reality. Acceptance also includes letting go; letting go of loved ones and places that have come to mean a great deal to me. Finally, the acceptance that there is no way to know what comes after. I fear it's simply oblivion. The show is over, the curtain comes down, and that's it, you're gone. That last bit for me, speaks of courage in the face of annihilation.