>>14156528
Couple of reasons.
The most obvious one I can think of is the performance. At launch the game had terrible performance and rigs that exceeded specs still had to use low settings to run the game.
The second thing is lack of replayability. The game spawned the exact same enemies in the same spots with the same objectives, meaning you got levels that played exactly the same with no replayability. I know they added the random objective mode as a response.
Lastly, a lack of progression. You have nine levels but that's it. There is no persistent customization or anything for multiplayer, meaning there is no reason to keep playing once you played it all. Singleplayer has artifacts to get but they only give you more points to unlock things in the SP campaign.
I'm waiting for the Enhanced Edition update. I preordered both EYE and Deathwing and I'm treating Deathwing the same way I treated EYE: Hold off on playing it until it's a somewhat playable state first.