Copying a work is often called theft, and it is not - it is copying, and nothing of substance has been taken.
I think most people agree that some limited form of protection for creative works is a fair trade for encouraging the creation of works which will eventually become public domain. But there is no natural right to "own" a thought, and "intellectual property" laws are merely a privilege which society grants in exchange for value.
But, the extension of copyright terms prevents works from entering the public domain, making that exchange a fraud. I will submit that creative works made for profit are based on ROIs measured in years, not decades. There is no legitimate need for, or public good which comes from "author's life plus 70 years," or 95 years after publication.
Why should MS-DOS still be under copyright? Lotus 1-2-3? SVR4? When they enter public domain, they will be useless. They are substantially so already, now add another 60 years (presuming no further term extensions). So, the tradeoff has already failed - the public will receive nothing of value in exchange for giving copyright protection for a time.