It's been my impression that in the US at least (and a bit of personal experience here) that there are many people attracted to Soto Zen that have a somewhat disdainful attitude towards what they see as the 'religious' end of Buddhism, and incorrectly take a couple of the positions of Zen to mean something they might not mean historically.
II admit i'm not totally in the know of the doctrinal positions of Soto Zen, but i've read stuff here and there, and have some experience of Zen practice, to me..it reads like what it is, which is a school of Mahayana Buddhism. Many forms of Buddhism (in fact arguably most of the Mahayana) takes takes a similar approach that we are already Buddha, that the pure land is obtainable here and now etc. However, it seems some Modern Soto folks have taken this kind of thing to mean that anything outside this interpretation is incorrect, and that it being "here and now" means that's the only
mode things exist in, that it's only
here and now. That is very different from what i've read of Zen, where Bodhisattvas are revered etc., and the general worldview is still Mahayana Buddhism.
I have never read anything from a "traditional" source Zen wise (though maybe it exists) that differs very much from typical Mahayana ideas in terms of worldview, the difference seems to me to be the premium on a "back to basics" approach regarding meditation, and a somewhat iconoclastic viewpoint - not denial of standard Buddhist doctrine. In fact, as an example (though this is Rinzai, not Soto I think), I just read a commentary on The Ten Oxherding Pictures - http://www.buddhanet.net/oxherd1.htm
It is so similar in theme (though of course the style is different) to reading texts from other Mahayana teachings, that if it weren't for the pictures and cultural backdrop, I wouldn't even know it was Zen.
My guess is (again I could be wrong) that you were talking to a western Soto teacher that has taken a "secular" approach, for lack of a better term, take it for what it's worth, if it jives with you..great. If not, talk to someone else!
"Just as a lotus does not grow out of a well-levelled soil but from the mire, in the same way the awakening mind
is not born in the hearts of disciples in whom the moisture of attachment has dried up. It grows instead in the hearts of ordinary sentient beings who possess in full the fetters of bondage." -Se Chilbu Choki Gyaltsen