You may not agree with them, but most football fans around the world think the CL is more important. So if City are to achieve the maximum fanbase/commercial exposure that the owners seek, then we have to be seen to be doing well in the competition and preferably winning it from time to time. Now you may argue that it is because we've been unlucky or that UEFA have fixed it against us but any way you look at it we have underachieved in that competition compared to where we are at as a team.
Not talking about round the world. I don't know one PL fan who would swap the league for the CL. And no City fan last year. While Scousers would have bit your hand off to do the reverse last season.