If a modder truly feels like that their mod is truly worth purchasing, then they can go for it, and try to charge money.
Considering how knowledgeable most PC gamers are, they will most likely be able to determine whether or not to support the modder, and whether or not the modder deserves profits for his/her work.
"Just for comparison Uncharted 4 was 20x bigger than Splatoon 2. This shows the huge difference between Sony's first-party games and Nintendo's first-party games."







