> Courts interpret the purpose of copyright pragmatically, as inducing authors to produce and disseminate works with the temporary grant of valuable exclusive rights.

I really do not understand how it is constitutional to retroactively extend copyright. How does this "promote the progress of science and useful arts"? It does the opposite, wherein copyright holders are encouraged to spend more time on works they have done where they were happy with the original copyright contract.

(The same can be said of copyright extending after death.)