: I don't get why they try to make movies out of games like Mortal Kombat when
: gaming has produced far better stories and universes since the 90s.
: Fighting games' story and lore are always pretty thin in a real sense,
: they don't seem to be good ideas for adaptations.

That's not why they aren't good for adaptations.

The reason is that the conflicts in these, and indeed most games manifests itself as purely, or mostly, physical in nature. This is fine when your primary mode of interaction is simulating the physical, but when you lack social or emotional conflict then you tend to have a boring movie.

Many games nowadays probably would not gain much from a film adaptation, but there are a few that would.