There's really no point in having divisions if winning yours doesn't guarantee a playoff spot.
Divisions are largely pointless as it is, though, especially once you remove the guaranteed top 4 seed.
If they want to make divisions more meaningful, they should change the schedule so that teams face divisional opponents significantly more frequently than non-division opponents.
Example:
Each team faces non-division opponents once at home and once away. That's 50 games.
Each team then faces its 4 divisional opponents 8 times each, 4 at home, 4 away. 32 games.
Would that skew things too much for teams in easier divisions? Probably. But that would make divisional rivalries a lot more interesting.