Cheers Tank .... Errrr why do they do this?
Arguments for it would include that the split makes relegation, title and European races grittier and more entertaining.
You're more likely to be playing against the teams that are vying for the same things you are. A win over a relegation rival means you're 6 points better of in respect to their position than if you had lost. It's there to try to make all teams have something to play for in the final games.
I like it, it leaves teams more in charge of their own destiny.
For instance, Rangers needed to be 2nd for 4th spot to get a UEFA place (Hearts playing in the cup final next weekend)
Aberdeen played Hearts midweek. A win would have put Rangers 2nd, and Aberdeen 4th. Aberdeen would've clinched a UEFA cup spot.
If instead, Hearts played Falkirk and Aberdeen played Dundee united, both teams could've won and no difference been made at all. We still had European football to shoot for in the last week of the season, and probably wouldn't have if their was no split.
When all is said and done though, the better team (Hearts) still pumped us 1-0 and thoroughly deserve their 2nd. From a TV ratings/crowd attendances point of view, it's important to have as many teams as possibly with something to play for at the end of a season.