I think some accusations of cultural appropriation are valid, and some are the result of the accuser's lack of knowledge, or possibly even racism or guilt over past or present racism.
For instance, often when someone is asked to give an example of cultural appropriation in the realm of spirituality and/or the occult in the modern day that is insensitive to the culture of origin, the example most often given is non-indigenous people continuing to burn sage as a spiritual purifier after being asked to stop doing so by *some* Native Americans.
Now, there certainly are many instances of cultural misappropriation in the world today, but that is not one of them, because Europeans have been smudging with sage for thousands of years. Sage (salvia officinalis) was burned and otherwise used by the Romans as a spiritual purifier and to ward off evil. White sage (salvia apiana), native only to the North American Southwest, is a related plant, and why in English it is called sage. Since white sage is only native to the Southwest of the United States, not even all Native Americans were using it across the continent, because it did not grow everywhere, just like tobacco does not grow everywhere and was therefore not used by *all* Native Americans.
Non-indigenous people are simply using another version of the same plant they were always using, that is at least a bit more native to where they are currently living than a plant from Europe. Besides that, "smudge" is a native *English word. It's the verbal form of the noun "smoke" and means "to apply smoke to something or make a smoky fire". That is why even today when smoke has been applied to something we can say that it has a smudge on it. It is such an old English word that it changes the vowel to change the part of speech, like changing "man" to "men" to make it plural, or changing the noun "road" into the verb "ride". In other words, it was in use before English speaking people were even aware of the existence of the North and South American continents. Most folks don't have a master's degree in linguistics as I do, but their ignorance doesn't make their opinion correct.
Personally, I don't mind if others want to use a word from my ancestral language to describe a practice common to many peoples across the earth, and I'll be continuing to use whatever words I want to describe what I do as well, especially if those words come from my own ancestral language, and I'm going to continue to use in an environmentally friendly way whatever plants that are local and/or ancestral to me that I feel appropriate. I actually prefer cedar/juniper/cypress, mugwort, birch bark, common sage, holy grass, rosemary and lavender, all of which are native to the European lands of my ancstors.
What does burning an herb for purification look like when its a Native American practice as opposed to a European or Middle Eastern practice, so we will know what not to do? Using an abalone shell to hold it and an eagle feather to swish the smoke around? My European ancestors held the eagle to be sacred as well. Eagle was depicted sitting atop Yggdrasil, the World Tree. And my ancestors lived much closer to the ocean, as I still do, to have access to shells than the Native American tribes that lived in the Southwestern desert where white sage grows. For any Native American tribe near the area where I live to use white sage and then say I shouldn't use it, would be like French people living in Paris and using a plant that only grows near Cadiz and claiming that's ok because its "European", and then saying that any Chinese who live in Paris have no right to it for their own traditional rituals that used a similar plant back in China because they are not of European ancestry. It is racism, pure and simple. Others don't have a right to your ceremonies, but they have all the right in the world to use the plant.
This same misconception applies to other items, aspects and cultural trappings that popular culture automatically associates with Native Americans. Sweetgrass is another example. It grows in all circumpolar regions, not only in North America, but also China, Tibet, Mongolia, Siberia, as well as the lands of my ancestors in Scotland, where it is called holy grass, and Scandinavia, where it is called sødgræs.
Additionally, we have actual archaeological evidence that the ancestors of Europeans wore skins and "moccasin" style shoes, wore cloaks made of colorful bird feathers (which in the Gaelic languages of the Celts was called a tuigen) and had bullroarers (dated to 18,000 years ago!) and skin frame drums, both for winnowing grain and playing. It was called a vétt in the Lokasena, and is called a wecht in Scots English, a dialect of English spoken in Scotland that was heavily influenced by the Norse (Clive Tolley, 2016). The Irish bodhran is skin frame drum, and some very old sources describe the framed skin used for winnowing grain in Irish Gaelic as a "bodhran". In other words, if "white people" use drums and feathers and wear skins in their spiritual practice, they are not appropriating something that didn't belong to their very own ancestors, and having those things forced from them by political leaders who converted to Christianity is not the same thing as our ancestors having willingly given them up, so they are still our birthright.
How many other accusations are based on a similar lack of knowledge on the part of the accuser, and also of the accused to defend themselves and also align their practice with a cultural root of their own? Maybe not even most accusations, but these few examples still demonstrate that we need to be careful about how much we allow ourselves to be manipulated by our own emotions into attempting to place limitations on other people, and we need to truly educate ourselves on the full story of things, especially if they elicit an emotional response from us. Finally, we should never give up the customs of our own ancestors just to appease another's lack of knowledge or tolerance of our own cultural ancestry.