Possibilities for commercial software?

[ROB]

> Only because it says so, right there in the US Constitution: Congress is
> granted the right to enact statutes "To promote the Progress of Science and
> useful Arts, by securing for limited Times to Authors and Inventors the
> exclusive Right to their respective Writings and Discoveries."
>
> As I said, it's about securing for authors the exclusive right to control
> who gets to make copies of their works.

You're missing the most important part...  A limited monopoly is
granted with the intent of providing an economic incentive for authors
to create, and therefore to promote the progress of science and the
useful arts.

The entire history of western copyright law, right back to the statute
of anne and even before to early grants of letters patent supports the
position that a copyright monopoly is granted not so much in
recognition of some natural property right in intellectual property,
but rather as an economic incentive to creators to create works which
serve to advance the collective body of human knowledge.