Steam doesn't let you actually rate a game; only recommend it or not. So, a game may be a 7/10, but if people can't recommend it for something like its monetary practices or frequent bugs/crashes, then it can end up on that list. That low rating doesn't necessarily mean people think it's the worst game on Steam, but rather that only about 10% of players think it's worth playing. Though, it's also worth mentioning that it has something like a 1.2 rating on Metacritic. It's generally considered a worse game than its predecessor in many aspects (including the readability of its characters, apparently. I guess they made some changes to the original characters' models that made them less identifiable?), and the reasoning behind shutting down the first one for this new free to play model was canceled. It's also been having issues with player attrition leading up to the Steam release, so the complaints don't seem unwarranted, but this probably wouldn't be happening if these players had some other outlet for their grievances.