I don't think a player needs to be strictly a one-club man to gain respect and trust towards his loyalty from the fans.

I respect players like Fernando Torres (previously of Atletico Madrid), Gabriel Batistuta (Boca Juniors > Fiorentina > AS Roma), Cesc Fabregas (previously of Barcelona) and Roberto Baggio (Fiorentina > Juventus) just to name a few.

Important thing is that they are loyal and passionate about the club they represent, not so much about how many years they have spent in the team.

Gerrard almost swayed to Chelsea couple of years ago even though he was born to play for Liverpool. Yet players like Batistuta stood by Fiorentina through relegation all sorts of crap even though he changed quite a number of clubs beforehand.

It's all down to the principles and characteristics of the player I suppose.