so far i didn't notice games being so dark. I agree, some scenes can be, but not the entire game. Maybe the dev forgot to turn on the lighting when creating. You should ask them about the reason.
Wow, that's an analysis I didn't expect to see here
Can't say I had problems with dark games tho.
Poor lighting setups, sure. Bad posing and collisions, yes. Graininess, yep. But darkness in general not really.
Extra, artificial light is usually added to make things "read" well on film and tv, that wouldn't normally be there. Sometimes it's done with paint style of the setting instead, like in the Harry Potter screenshot. Normal roots wouldn't look like that.