His finishing is awful? Have you seen some of the goals he's scored this season? Even Ronaldo couldn't finish like Cole did against West Ham both home and away, and Blackburn and Everton away.
And no, he doesn't disappear in big games. If you're basing that on evidence of the last few games of the season, he disappeared entirely against every team because he was absolutely knackered. Cole played 54 games last season, and ran himself into the ground in the vast majority of them.
But on evidence of last season on the whole, if Joe Cole isn't good enough for you then maybe the rest of our squad isn't, because bar perhaps Carvalho, Cole was the star performer of last season.