tl;dr Jagielka is a bad captain because he doesn't shout at refs and isn't like Ferguson. Who was, let's face it, a complete psycho. I mean, he's a lovely man off the pitch allegedly but he could be pretty horrible on it, and a captain's no use if he keeps getting banned for beating up opposition.
Coleman is the most obvious choice for me as a replacement. Baines should never be captain. Too quiet.
ETA: do all captains in the EPL act like this archetypal heroic captain you all want Jags to be? Apart from Noble.