What you are doing is mistaking influence with outright copying.
A musician could be influenced by Jimi Hendrix, Kraftwerk, Beethoven and Miles Davis, plus many more. No artist is influenced by exactly the same combination of previous works, in exactly the same way and by the same amount.
This inevitably results in randomness in influence and individual innovation.

With all do respect, what you are doing is mistaking how the copyright law that Nina Paley is speaking out against actually operates.

Copyright doesn’t just prohibit “outright copying” as you put it, but it also prohibits the creation of what are known as “derivative works” which are very broadly defined. The prohibition against derivative works is in fact a prohibition of the very kind of “influence” that you claim to be in favor of.

Let’s take your own example of a musician being “influenced by Jimi Hendrix” for instance. Presumably, you are familiar with Hendrix’s famous cover of the Star Spangled Banner which he played at Woodstock and elsewhere? Questions: Was Hendrix “outright copying” that song in your opinion? Or was he merely “influenced” by it as you put it? Or was it something else in-between those two characterizations?

Fortunately for Hendrix, the Star Spangled Banner was in the public domain by the time he performed it. But that fact also goes to the heart of Paley’s argument – recognizing that longer copyright terms (life + 70 years!!?) starve works out of the public domain and thus prevent artists from creating derivative works from them (which doesn’t even deal with the question of “outright copying”).

Another question: If the original orchestration of the Star Spangled Banner remained in copyright in the 1960s due to a long copyright term under law, do you believe Jimi Hendrix would have had a fundamental right to perform his version of the song? Or do you believe that the Francis Scott Key estate (or other third party players or corporations with the rights to the tune) should have had the ability to prevent him from doing so? Wasn’t he “copying” the song under your definition? He used all of the same notes within his version, right? Or was he merely “influenced” by it, as you use the term? If someone using Mickey Mouse in their independent film is “blatantly copying” in your view, then clearly Hendrix was “blatantly copying” Francis Scott Key and should be considered a moral reprobate in your (thankfully wrong) opinion.

This is why many commenters here are calling you out on your ill-considered and blatantly false remarks that “all art is based on new ideas and innovation”. If you would be so kind as to provide links to some of your own works, several of us would no doubt easily demonstrate that your “original” art could easily be characterized as a “derivative work” of an artist who came before you.

The contours of copyright law and the human behaviors it legally prevents are far broader than you seem willing to admit. That is what Nina Paley is rebelling against. That is why she and her sympathizers are right, and why you are wrong.