It seems to me that some principles of eastern religions have appeal in the west, but not necessarily the whole cultural aspect.
Religion is often intertwined with culture, as a subset of culture. If religion is extracted from culture to attempt to be isolated and transported to a different culture, then it can be tricky to see where that separation ends. Art, language, family structure, level of development, knowledge of other cultures; these things can all be intertwined with religion.
Indeed. In my (unincorporated) neighborhood, we have about 15% Asian population. The Eastern religion meeting places around here certainly seem to be highly associated with different countries. There are quite a few Korean Christian churches around here, as well as a Sikh Gurdwara, A Vietnamese Buddhist temple, and a good sized Hindu Temple all within a few miles from my house, and they all are quite busy, even to the point that the police show up to direct traffic at the Buddhist temple when they have their meetings.
A few years ago, my ex stopped by the Buddhist temple to check it out. They welcomed him, but seemed a bit leary of a westerner. (They just happened to be trying to repair their plumbing, and the way they were repairing it would have poisoned their water supply if my ex hadn't shown up and pointed it out. They warmed up a bit to him after that, but my ex never did go back there.)
So a lot of western people sitting around a temple statue with eastern physical features and based on eastern art- that setting just doesn't appeal to everyone. It feels to some as though they're part of something foreign, or something distant. Worshiping a foreign culture. The Abrahamic religions are originally foreign to North America or Europe as well, but Christianity has been intertwined with western culture ever since it got picked up in the Roman Empire, so it's sufficiently absorbed to the point of feeling to many as though it's a core aspect of their culture (like how Jesus is often a white guy with long fine brown hair in art for some reason).
This cultural tension might go both ways. I know the Vietnamese and the Cambodians around here don't always get along--they bring their cultural baggage along with them. Old habits can be hard to break.
It seems to me that "filtered" aspects of eastern religions are popular. For example, American Transcendentalism was based on numerous things from a few cultures, which included the Upanishads. But it doesn't have a foreign feel to it; the earliest essays were written by Americans. New Age beliefs often incorporate elements of western and eastern religion, like reincarnation. Buddhism is often practiced but from what I've observed it's often a sort of minimalist form with fewer cultural ties to east Asian countries in art or setting.
This might be the only way for it to succeed, given the cultural strife between the different Eastern nations.
To continue that point, I also think variants of agnosticism and syncretism appear to be on the rise in developed areas, maybe due to increases in exposure to multiple cultures. Rather than looking to a local or foreign culture and saying "this is the specific belief system I accept as true rather than the others", people seem more likely to simply get inspired by a few concepts from different areas.
It might also be a subconscious attempt to separate out the cultural strife from the beneficial philosophy and practices.