Having a top 6 means more clubs have more to play for right through the season, meaning more fan interest, more TV views, more bums on seats, all equalling more dollars. in the last few seasons the Nix's fight for the finals has translated to huge interest and big home crowds. The same goes for all finals contending teams down the years.
I for one am perfectly happy to see the likes of the Nix or an excellent Mariners side sneak into the finals. Where's the harm? The stats show that they are highly unlikely to win it anyway.