There used to be no free version at all. (only demo)

They need to earn money you know?

Also, keeping everything backward-compatable would
seriously limit the speed of implementing new features.

Most of the time you only need to rewrite a part of the code.

Some small recent games of mine:
Griefer 4k http://damocles11.byethost9.com/griefer4k.html
Kobold 4k http://damocles11.byethost9.com/kobold.html
Cave 4k http://damocles11.byethost9.com/cave4k.html