Carroll's transfer hasn't worked out just yet, he's having to adapt to a new style of football but we bought him knowing that he could cut the mustard at premiership level. Did anyone really expect Suarez to be as good as he is as quickly?
Your latter point is actually critical in understanding the Carroll "problem". Suarez has been so amazing in terms of his ability, his commitment, his desire to win, everything, that everything just clicks into place with him. I believe Kenny wanted to build a Toshack and Keegan pairing with Carroll and Suarez, but the Uruguayan has been so phenomenal that the partnership hasn't really taking the front seat. We also needed results, and the shortest route there was just to aim everything at Suarez and watch him go. That won't work forever.
For now Carroll is our Plan B, so there's really no point in "supporters" wondering why he's had so "little" impact (1 goal in 4 games, including 2 as a substitute, with a goal and an assist wrongfully disallowed hardly seems like he's done nothing, does it?).