We're talking a lot about "selling out" but maybe not so much about the bigger issue of his work leaving his control and becoming a property that would be used all sorts of weird ways.
If you want a cautionary tale, look at the Iron Giant. A thoughtful and interesting character whose whole arc is choosing peace is now shoved into things like Ready Player One [1] as a fighting weapon.
It's hard not to think that Calvin wouldn't get reduced to some Dennis the Menace type character that misses the point were he to leave Watterson's control.
If you want a cautionary tale, look at the Iron Giant. A thoughtful and interesting character whose whole arc is choosing peace is now shoved into things like Ready Player One [1] as a fighting weapon.
It's hard not to think that Calvin wouldn't get reduced to some Dennis the Menace type character that misses the point were he to leave Watterson's control.
1 - https://www.inverse.com/article/42896-ready-player-one-iron-...