Yes, you will always get the artist in the garret who will produce wonderful works whether or not s-he gets compensated, but most need to be compensated for their work, and such compensation would not exist except for copyright. But compare professional programs with the offerings of freeware and shareware. Not only that, they also show a singular lack of originality. Most are knock-offs of the features and user interface of the professional programs. Even in the realm of software, lack of strong protection does not lead to a glorious renaissance of creativity.
Lets face it.
Compensation is a motivator, and protection leads to compensation. It is simply not true that many creators would create works regardless of the amount of copyright protection their works will receive.