Haskell spotted in the wild

Age of Empires 2 clone(OpenAge) has a game server written in Haskell(i assume for the thread safety or something)
https://github.com/SFTtech/openage-masterserver

>>4
Lets be realistic, writing a game is just one of requirements for success in online gaming.
you need:
1.Host websites,forums, optionally code repos(do you trust github?).
2.Provide game servers(p2p games are either crippled in bandwidth or limited with NAT firewalls). Hosting and server cost money.
3.Somehow finance your expenses, usually within the game: so microtransactions, paid DLC. This would likely mean it'll be closed-source, to prevent cloning and stealing of in-game data.
4.Closed-source means you would target windows first and linux support will be relegated to "they'll will figure it out with Wine".
Hope this explains why Big Games on linux don't exist or are secondary to windows.