Dont change your bars just because someone told you that they look narrow! There is no correct width just a rule of thumb starting point that says "about shoulder width". Thats about as accurate as telling you your front hub should be obscured by your bars if the sem is the right length (complete BS).

Are you comfortable? If so tell the guy you think he would be able to ride the next smaller frame to whatever he is riding, then sit back and switch off while he justifies his bike to you.

People that make comments on your bike fit are usually the ones that arn't really comfortable.