I dunno, it's just something I feel when I look at the players in the team. Apart from Suarez there's nobody there that plays in a particularly purposeful, incisive or dynamic way. I'm not sure how to describe it exactly, but when I see Suarez get the ball and set off on a run I think "hmm, something might happen here", whereas if it falls to Downing I'll think "ok, this is going nowhere, he'll probably have his cross blocked by a defender or kick it over the bar". Similarly, when the likes of Jordan Henderson or Charlie Adam get the ball my thoughts are that they're most likely to pass it to someone else rather than actually make anything happen themselves. Andy Carroll is just rank average, so no need to worry about him either. It's all a bit different when Gerrard is in the team, but he's missing so often these days that you wonder if he'll ever be as dynamic or threatening as he once was as well.
I'm not sure what it is, but when I look at the Liverpool midfield and Andy Carroll, it just seems so obvious to me that the right balance is not there somehow.