Mr. Boat, I think there are many kinds of games, not just for entertainment
but for "edutainment" as well. A person who loves games may at some point
want to learn how those games were made. A game developer who releases the
code of her games under libre licenses is supporting the learning process of
people who want to create games. Making small changes in the source code of
an already functional and useful application or game can be very
constructive.
As for the graphics and other assets that are consider non-functional, and
for that reason not necessary to be free, I don't agree with the FSF. Those
"non-functional" components are part of the cognitive ergonomics of the
software which help optimize human interaction with the system. As such,
these "non-functional" components should be libre as well so that the
community in general can share them and build upon them.
In games, these non-functional components are specially important. Remove
these from a great game, remove its graphics, music and story, and to an
end-user the game may seem like a piece of crap, even if the source code is
beautiful.
