I don't see why adopting local cultural forms is such a bad thing. When peoples join the universal Church, they bring their culture with them. Historically, this often added a local flavor to preexisting Catholic feasts
Discussion
Local culture can contaminate. I prefer the pure to the profane. Separation and purity are integral to the concepts of holiness, sanctification, and sainthood.
The New Testament was written in a specific time and place in history, namely, amidst a Jewish and pagan milieu in a corner of the Roman Empire. The writers were influenced by the cultural practice of their time, and Scripture itself is full of cultural references that don't apply directly to the present day.
Tell me where you are finding the pure, unadulterated cultural practice of Christianity.