Is borrowing from another culture

acceptable?
Someone raised this yesterday and questioned whether it was insensitive to borrow from something like Australian aboriginal "dot" painting, New Zealand Maori carving or the painting style of Constable. I assume it would be possible to add to that list with haiku from Japan, Irish crochet lace, Estonian lace patterns, Cowichan knitting patterns, music using the sitar from India or the gongs from the hill tribes in Cambodia. The list is endless.
I know Prince Harry was roundly criticised for trying to reproduce a "dot" type painting when he was at school. It was considered improper. One of the aboriginal elders said "He's just a boy. He does not understand." I have heard a didgeridoo (a very long wooden pipe) played by a non-aboriginal. He was "given permission" to learn and play but told he would never master the art because he was not an aboriginal. The late Judith Wright was once warned not to tell a "Dreamtime" story because it "belongs to us" - the "us" in question being members of an Australian aboriginal tribe.
One of the issues I have come across in my work is the "death" of languages. Languages die out if nobody uses them. If they do die out then we lose more than language. We lose a way of life, a way of thinking, the stories that have been created in that language, an understanding of the world from another perspective. There have been active attempts to "kill" languages for political, cultural or religious reasons. Other languages die a more natural death. A community may be taken over by another community. The language is not taught in schools. Then it is not used and taught at home.
It can happen very rapidly. My brother in law's parents grew up speaking Cypriot-Greek. He speaks Cypriot-Greek with some English thrown in when he does not know the Greek word. His two children speak almost no Greek at all. As the sister of their daughter in law I know a few words but my father knows none at all. It has taken two generations for the language to be almost completely lost within one family. It was not used. My brother in law was educated in English and so were his children.
Cypriot Greek is not going to die out though. There are other people who use it as their everyday language and there are enough of them to preserve the language and the culture which goes with it. The vocabulary has kept pace with the modern world.
We are losing aboriginal languages though and we are likely to go on losing them. The numbers of speakers of some tribal languages are so low that even intensive attempts to preserve them are not going to work. One reason for this is that the languages do not have the vocabulary or the concepts to cope with the 21stC. They simply do not work as a tool for communication in the world people now live in. Another reason is that they are not being passed on to other people.
Vocabulary and concepts have been "kept secret". Outsiders have not been allowed to use them.
When this happens anything of cultural significance is almost bound to die out.
Culture is a living thing. If you do not use it then it will die.
If you borrow something from a culture other than your own then I believe you should try to understand it as best you can. It should be treated with respect. If it has genuine spiritual significance for some people then that should certainly be respected. But, if we are to preserve some of those skills, then they must be used and go on being used.
Artists - and writers - "borrow" (or are influenced) all the time. If they did not then our creative lives would cease to exist.
I think if I wrote only about those things I had a direct experience of then I would cease to write.