It is funny how some so-called "traditionalists" oppose syncretism.
Historically, all forms of spirituality are highly syncretic. This is because traditions are nothing but disposable vehicles, by which universal truths are transmitted.
All traditions have some truths. All truths are compatible. Therefore, when one person is influenced by two or more traditions, the natural tendency is to synthesise them into one system.
Examples:
In the Coptic magical texts, four magical traditions play equal part: Jewish, Greek, Egyptian, and Christian.
In Agrippa's Three Books of Occult Philosophy, every page referred to dozens of exotic traditions.
In Daoist magic, people use pseudo-Sanskrit sounds.
In Traditional Chinese Religion, people worship Buddhist, Confucian, Daoist, and Shamanist deities at once.
In many modern Chinese religions, you even see Christian symbols, such as angels. Many newly-written sacred texts have Jesus conversing with Buddha, Confucius, and Laozi.
Tibetan astrology is a fusion of Chinese astrology and Indian astrology.
Conclusion:
The reason some people grasp onto one tradition or another tradition is because they have no true spiritual experience. For those who know true spirituality, efficacy is the measure of truth.
True traditionalists, such as many Daoists whom I know, are supportive of the New Age enterprise. They are also supportive of Neo-Paganism and Wicca.
Do you think the ancients rejected innovation and syncretism? If so, why did Caesar describe the gods of the Gauls in Roman terms? If so, why did Plutarch, Plotinus, and Iamblichus freely discuss the religions of the East?
Truth is universal. If something is true, then it is true anywhere, anytime, for any person. Traditions have nothing to do with it. Unfortunately, people forget this when they discuss religion.
Scholarship has no direct relevance to spirituality. A spiritual teaching is invalid unless it can prove itself. Scholars can talk. They can also write abstruse articles read by other scholars. But can they demonstrate any spiritual accomplishments?
This is especially poignant in relation to my country, China. Because most scholars of Confucianism, Daoism, and Traditional Chinese Religion do not believe in ancient things. Therefore, they churn out books after books of scholarly "facts," which have no bearing upon reality.
True religion is only found in the villages, in illiterate shamans, in mountain hermits.
Anyway, I doubt what I say will convince people on this forum. I write here only because a friend asked me to.
Blessings for all.