Because it doesn't have configurable input binding. How titles still get released this way, I have no idea. Worse, the default controls are the WASD+other random letters junk that was never good, let alone being passed as an expected default. Will revise when the game might be updated so it could actually be played.
This is equivalent to what would have been a free Flash back when while the person making it iterated prototypes while making the actual game. Everything feels incomplete and placeholder: There's zero feedback when you're hit, the "terrain" is just there with no interaction between player or monsters, the upgrade choices are bare-bones and repeat very soon. Enemies can get "trapped" between you and your on-screen guns, basically immune unless you can run fast enough to get them out of your pseudo-blind-spot bubble. Buy only if you want something to play for a minute while your kettle heats up or something.
The 1.2 patch completely changed Grim Dawn, a longtime favorite game, from being an amazing, stellar, game to something that I can't even find the drive to open. The genres have completely changed in this patch. The patch added some crazy precise "dodge a boss's ultra-skill or die" mechanic. The game is now all about your precision reflexes instead of your build. The game's no longer fun and enjoyable to play but leaves you exhausted and irritated. The game's still great outside of bosses. But you can't play the game without doing the now-terrible boss fights. And the developer has doubled down on this, how they want the game to be all about action and player "twitch" skills now.