Plagiarism is considered unethical and immoral, even before it becomes a violation of rules... one should not plagiarize, not because of the forum rules, but for ethics.
If you wish to use content which you didn't create, you can just quote it... There is no harm in doing so
Stealing from any organization is never desirable. No organization can succeed by stealing someone else's content. Cryptomus has done very wrong by plagiarism. I feel guilty because I promoted such a company through signature campaigns.