RMS basically has the right answer, but only limited to his field of work. Copyright and patents are both examples of capital, or private property, this meaning concepts of "ownership" which go beyond personal property. Personal property is the things you use as part of your everyday life, objects which are like an extension of yourself. This deserves protection. Capital, or private property, is things you own in order to exert power over other people, to restrict their life in accordance with your interests. This is the concept which needs to be discarded, which creates a ruling class controlling a working class, is precipitating fascism and destroying the ecosystem etc. RMS is ethical enough to get this when it comes to the things he's familiar with, but since he's so focused on the world of software he hasn't quite made the leap to realise that it being possible to own things like factories or the homes other people live in is the same kind of problem.
Copyleft, incidentally, makes use of the law of "copyright" to create a relation which doesn't work in the personal interests of everyone, but works in the interests of the community. This is what makes it different to the normal use of "copyright". (In quotes because it is actually a restriction, not a right. Taking away the rights of others is not a right.)
"Money is the root of all money." -- the moving finger