The formula for placement should never be revealed.
There are already enough wars over KD v. SPM, SPM v. W/L, KD v. W/L and what each of these stats mean in each of the different game modes. If we knew the exact formula for league placement, each side of these wars will just start another war, league style.
If we knew the formula, people will just complain about why their strengths aren't the most weighted.
Further, and this is the most compelling reason it ought not be revealed. It would encourage dashboarding and rage quitting even more. If we knew KD, for example, is the most weighted factor, then, well, we all know the length some go to get a high KD.
Lets face it, if you're relatively experienced in this game, you'd know who deserves Gold v. Masters, Iron v. Gold. And if you're honest in assessing your own game, you'd know the division to which you belong (except for that poor bastard who's stuck in Platinum Rank 1 from season's beginning to end.)
So when people knock this DV dude for the ostensible inconsistencies in placement, I think there's actually a reason and method to his madness.