I've always maintained that it's really hard for teams to promote since older teams tend to have more cash and/or better players and can maintain better rosters longer. I've finally gotten my team to a competitive level in D.II, but I'm out of cash. Older teams can have "break even" rosters and not turn a profit, but still have a cushion for roster upgrades. I cannot make an immediate roster move and I don't have a cushion, so I have to be creative if I want to try and improve my team.
I think either they economic system needs to help churn teams from the bottom to the top faster, or find some way to make the bottom divisions more exciting somehow if teams are just destined to stay there longer, such as develop more of a "league history" archive. I feel pretty entrenched in my D.II league right now since I've been it for a bunch of seasons already (sort of stagnating), but the other teams are mostly pretty experienced so we make it fun for each other. The lower divisions don't have those sort of teams, and managers are more likely to quit, so something needs to make it fun for teams in those leagues that have a hard time promoting so fast.
Don't ask what sort of Chunks they are, you probably don't want to know. Blowing Chunks since Season 4!