Someone else's definition of progress could include a heightened respect for comic strips as art, rather than base fodder for merchandise and commercial exploitation. Watterson's stance did help with that, at a time (late '80s) when it was still a very niche position in the US.
This is particularly true for comics, which have historically been seen as fodder for other industries in the US and need all the attention they can get as an art-form in their own right.
> In Congress’s first Copyright Act of 1790, as under the Statute of Anne, copyright persisted for 14 years, with the possibility of a 14-year renewal term.
> Under current law, copyright in a work created by an individual author lasts for the life of that author, plus an additional 70 years.
https://constitution.congress.gov/browse/essay/artI-S8-C8-3-...
> “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.”