It's my impression that so much of what is practiced in the US these days is far more "Zen," or the American new-age post Beat type stuff that has cemented itself well in the practice of Zen, but, to me, is now Zen, but really not so much Buddhism. I have noted in some Zen sanghas almost a reluctance to acknowledge Gautama Buddha, and a suggestion that the Agamas/Nikayas are to be forgotten or ignored. I feel that Zen in the west has evolved, and in doing so, moved further away from the original path and onto a path almost entirely of its own design. The evolution does seem to have root in not early Mahayana, but in later Mahayana, where there seems almost a perjorative attitude taken toward the early teachings of Buddha. What seems to have emerged is a grand tradition of storytelling, with later sutras designed to characterize the Buddha as a god, a mythical deity, a supernatural being. I have the sense that some of the Zen patriarchs were really carving out for themselves new philosophical territories at the expense of what they themselves were taught when they were young monks. Dogen may be just one example of this phenomenon.
I note that a few years ago, after sitting sesshin for a few days, all of us sitting, and sitting and sitting, with no instruction and no perspective on the sitting, one of the priests at the zendo, in a private moment, cut loose with " all this sitting is just bulls**t!" I think what he was trying to express was that in Zen, the marathon sessions of silent sitting were not what Buddha taught, and seemed not to be doing much for anyone other than seeing whose knees and backs could withstand the torture the longest.
There is such a beauty and strength to Mahayana practice. The bodhisattva ideal is absolutely the proper template for practice in the modern world, and it's my feeling that Gautama himself is still such a strong example of that ideal. Early Mahayana took the traditional practices and in so many ways expanded and energized the teachings, in a very authentic way. Yet, modern Zen may need to be careful that in throwing out the bathwater (the Agamas) it doesn't toss out the baby (Shakyamuni Buddha) as well.