"We don't meditate we just sit. We don't use a method because we don't wish to achieve anything. Methods are designed for attainments. We don't have any goal orientation. Zazen doesn't lead to enlightenment - Zazen ist enlightenment."
How can you speak with such people?
Speak to these people by being honest, and speaking of what your actual experience of practice is; not some idealistic pretty sounding philosophical crap. I would ask your friends, Oh really, you don't meditate, you just sit, why do you sit? Why do you really sit? Why do you practice? Keep asking till you get an answer that a Five-year-old would understand. Anything less doesn't yet get to the heart.
They speak of not wishing to attain something, not having any goal orientation. That's great, but is it true? Is it what they really experience? The fact that they want to "not wish to attain something" is itself an attainment. "Having no goal" is a goal. It they think they're really there, they're probably full of crap. If they truly realized no goal/no attainments, that they would right now drop off body and mind of self and other and see into their true nature.
The non-attainment, non-goal orientation of Soto Zen is a teaching style or upaya, the Sanskrit term meaning "skillfull means." These are the different ways of teaching different people. Soto is a school of Buddhism, of the Buddha dharma; the Buddha dharma is the way, the path to enlightenment. Even in Soto, the goal, the attainment is Enlightenment. Their means of teaching this, of realizing this is through letting go of the goal oriented, attainment oriented mind, this mind which seeks something outside of themselves.
Non-enlightenment talk comes from the Zen and the Mahayana tradition at large. In some schools of Buddhism only the realization of the Absolute is seen as what matters. This is seen from the Zen perspective as the "stink" of enlightenment, the "stink" of Zen. When this realization is embodied in everything one does, when the Absolute and the Relative are in perfect accord, then, no trace of enlightenment remains, and this traceless enlightenment which continues endlessly is what is spoken about in Zen, and the Soto school. Your friends seem to be using the words of the dharma to justify their own views and practices. This is why the eightfold path begins with Right View. To steer clear of this kind of confusion. The dharma can easily be used as a means of defending our prejudices and our attachments. This is among the reasons that working with a teacher is so important.
Back to the question of "Is Zazen Meditation?" The real question is, is that question important? If so, why is it important? If Zazen is meditation, what does that mean? Many masters have given Zazen, or Zen Meditation instructions. The word literally means "seated meditation." Does that make is meditation? If Zazen is not meditation, what does that mean? What are the implications of that view? My teacher Shugen once told me, "Whatever you do, don't think you know Zazen." His teacher Daido Roshi once taught "Whatever we are running away from, whatever we desire, whatever side we're falling into, we've got to see the other side as part of the process. When finally neither side gets in the way, that's when the golden body of the Buddha manifests of itself." How do we not get caught in Zazen is meditation, or is not meditation? The truth doesn't lie in either side. It doesn't lie in both sides. Where do you find yourself?