Personally I tend to agree with the late Jamgon Kongtrul, an important figure in the modern Ri-me (nonsectarian) movement within Tibetan Buddhism who said this: "it is important for the values of Buddhism to imbue a culture, not for those of a culture to imbue Buddhism."
The context for this is given below, which is taken from the Translator's Introduction to The Autobiography of Jamgon Kongtrul: A Gem of Many Colors (translated into English by Richard Barron). Note that the autobiography was written by the first Jamgon Kongtrul (who founded the Ri-me movement in the 19th century), while the quote is from the third Jamgon Kongtrul, who died in 1992.
In the mid 1980s, I had the opportunity to interpret a public talk given by the late Jamgön Kongtrul Rinpoché in Victoria, British Columbia, Canada. During that evening, Rinpoché spoke of the ri-mé approach. He defined this quite succinctly: "To adopt the ri-mé approach means to follow your own chosen path with dedication, while maintaining respect and tolerance for all other valid choices." The operative word here is "valid"; what is meant is not a blanket acceptance of anyone’s doctrines. A khenpo of the Nyingma School recently remarked to me, "We are to maintain a pure outlook toward all other beings, but not necessarily toward their opinions." This is anything but a sloppy approach. In insisting on the freedom for everyone to choose a spiritual path, and on the validity of all authentic alternatives, the ri-mé approach is broadminded, avoiding the all-too-common pitfall of exclusivism, but does not promote simplistic beliefs. Our prejudices concerning spiritual matters may come from issues that are personal, ideological, or cultural, but regardless of their origin, these prejudices can place severe limits on our own ability to grow spiritually. Jamgön Kongtrul also stressed, in that evening talk, that it is important for the values of Buddhism to imbue a culture, not for those of a culture to imbue Buddhism. The ri-mé approach was not intended to serve some other agenda, but to provide a context for honoring the contemplative life in all of its manifestations.
Jamgön Kongtrul Lodrö Thayé was born into a culture that had been host to the Buddhist teachings for a millennium. Throughout its long history, the Tibetan tradition of Buddhism has seen many periods of mutual tolerance, particularly in the early stages of its development, when there was much interaction between the schools. We find accounts of many individuals who studied with masters of all schools and who in turn taught students from all schools. But there have been just as many times when political rivalries and power struggles led to sectarian polemic and even outright hostility. In a few cases, entire schools were suppressed. It would be bad enough if the grounds in such cases were (as claimed) doctrinal, in the name of keeping the teachings pure, but all too often a more mundane purpose was bring served. For people interested in more details on this subject, I can highly recommend Chapter 17 ("Jam mgon Kong sprul and the Nonsectarian Movement") in Gene Smith's excellent book, Among Tibetan Texts: History and Literature of the Himalayan Plateau. The extent to which Buddhism imbued Tibetan culture over the centuries is nothing short of remarkable, but the extent to which that culture imbued the Buddhist teachings often resulted in unfortunate consequences.
The whole Translator's Introduction is online here.
[pic at top of post is the 4th Jamgon Kongtrul, it comes from here.]