that copyright licenses aren't mutable by anyone but the owner
Well, sort of. Certainly if you've released something under CC0 or WTFPL, any derivative work can be "relicensed" however they want. MIT and BSD and CC-BY have some fairly trivial conditions that must be respected and fulfilled, but otherwise a derivative work can still use a different license.
I don't think many people care about the particulars of open source software licenses except in the context of producing derivative works.
Comments
Well, sort of. Certainly if you've released something under CC0 or WTFPL, any derivative work can be "relicensed" however they want. MIT and BSD and CC-BY have some fairly trivial conditions that must be respected and fulfilled, but otherwise a derivative work can still use a different license.
I don't think many people care about the particulars of open source software licenses except in the context of producing derivative works.