They were nomadic and did not cultivate the land. As a result, they had no recognized concept of property. In addition, many tribes, e.g., the Lakota, were polygamous. That was an absolute no-no to any 19th-Century American who wasn't a Mormon.
they believed that their loin cloths were disrespect full in many ways. and they just did not like their copper skin
The NA's were considered the enemy by the settlers, and as is typical, the enemy is demonized to make their genocide seems justified.
well think about it, send your average American teen over to a tribe in Africa, you'll find out they wouldn't approve of their lifestyle. Why? because it's different from how they were raised and what they know
Most people disapprove of things that are different, not all but most.
If you're going to use political correct terms such as Native Americans (american) or First Nations (canadian) please use the correct term for 'whites' which is Caucasians.
They didn't. That was a convenient lie they told themselves in order to justify taking the land for themselves and killing those Native Americans. Most settlers knew otherwise or at least suspected otherwise, but went along with the propaganda basically through greed. This type of thing even occurs today throughout the world. People who want something will try to make it seem that those who have it are unworthy to have it and make up reasons to take it from them based on that.