Opening the game's data to modding almost guaranty a longer lifespan than keeping the game "closed and finished", and so, better sales.
A game like this would be quite easy to mod, as it's 2D pixels tiles based.
I would love to see :
Maps, tiles, monsters, heroes, texts, quests, traps, sounds, musics... Even without ingame editor, but an easy to mod files, and a menu to (un)check mods to play with. I'm thinking about Dominions, Conquest of Elysium, Rusted Warfare, Factorio, Rimworld...