That said, Buddhism put into practice and fully lived out does not generally seem to create nihilists, but rather, compassionate realists. When, as with the author of Suicide Note, it is believed that "God is Dead" and there is nothing to replace Him with (like the Buddha-dhamma), then nihilism is a likely result... or so it would seem to me.
"Hatred is never overcome by hatred, but only by kindness. This is an unchanging law. Overcome greed with generosity, overcome lies with truth, overcome evil with good" (from the Dhammapada) Does this really sound like nihilism to you? Far from admonishing us to do whatever we want because nothing matters, the Buddha is setting out a way of life where things matter because we are feeling, experiencing beings.
I think the person that commits suicide because life is meaningless is not bad, merely sick. That is the real point of Buddhism. It is not intellectual excercise, it is medicine for the human condition. Surely you Orthodox are people of good will and see that the human condition has sadness and grief? How do we deal with this? The Buddha had answers: moral living, discipline, asceticism, kindness, compassion. It is not an intellectual excercise, it is a way of life. Jesus said the same things, people that obeyed his words and put them into practice were building their houses on solid rock, right? Wisdom is not a religion, it is available to everybody that honestly seeks truth beyond cultural conditioning, fad, or prejudice.
Buddhism indeed affirms that life is without purpose in the absolute sense. Life just is. However, this doesn't mean we can't choose to live purposefully. And actually as the Taoists note, the great blessing of life is that there are no rules to it set out in stone for us, we are free to play here, as the Hindu's say, the world is a manifestation of Leela, sport or play. The aesthetics in life, found not only in the happiness but in the sadness, create the palette upon which we create meaning for ourselves. Having said that, the Mahayana Buddhist path offers us the Bodhisattva ideal, to live for others as the highest purpose in the relative world, but in absolute terms, self, others, and all other concepts do not apply. Until we realize this though, living altruisticly is medicine for our condition. Mahayana Buddhism in short offers us a noble, sacred life in place of banality and nihilism.
I'm buddhist because I'm the teachings of the Buddha have always appealed to me, meditation is something I'm interested in, and I'm a queer person (I'm bisexual and transgender), and thus Orthodoxy is not liveable for me because I don't see the evil in loving people of whatever gender I feel drawn to. I respect alot of Orthodoxy's teachings but I simply don't agree with its moralism or authoritarianism. Unlike an Orthodox hierarchy's insistence on tradition being infallible, the Buddha instructed us to deeply question and analyze everything (including himself), looking for only that which leads to happiness and is borne out in our own experience as wise and true. I do not believe in objective morality as a bunch of rules, I believe in treating other people the way I want to be treated, using skillfull means to seek the happiness of others. People are individuals and Buddhism respects the various karmic affinities we each have. That is why I am not Orthodox and I am a Buddhist. There are 1000 Dharma Gates; may you enter through one.