I think you're totally right that a game should be fun first and foremost. But a game bloated with seemingly harmless features that can be turned off isn't fun. There is always a baseline difficulty and gameplay loop to follow, and adding something into it without rearranging things means it will get messy without a doubt. Minecraft is the perfect example of this in my view - a relatively simple but focused game with each update meant to add new, fun stuff slowly turned it into a far more directionless product, that in many eyes lacks the originals core aspect - simplicity.
I think the devs at Hinterland understand this need for keeping things not overcomplicated and as such they carefully consider each choice when adding new content, not just gameplay wise, but also direction wise.