The reason for "No Derivatives" is that RMS doesn't want his words to be changed. Some text files inside Emacs are (c) RMS, but with a permission to copy and distribute the entire article verbatim.
Not especially, Stalman campaigns for free software and he has reasons why he thinks it's a very good idea. Those reasons don't really extend to interviews as far as I can see.
That's because despite his dogged persistence on the FSF GNU bit, he really doesn't care about Freedom.
You think what he has quite literally dedicated his life to doesn't count simply because he didn't grant you permission to put words in his mouth?
I think RMS is restricting my freedom to put words in his mouth.