Desecration...But why?

If you didn't already get it, this thread will be about the unholy death knights talent desecration.

Please note that this is not a QQ thread about DKs being overpowered, because they are not.

I simply wonder why they have such a huge control against, well almost everyone, and yet so great burst with stuns and silences.

When I play arena (not on so high rating, I know) I have the 4 seconds of movement impairing immunity from my wolves to kill a death knight. And if i try to switch target there is always a desecration lying there waiting for me, keeping me slowed to 50% movement speed all the time.

And I think the most ridiculous part is that 4.0.6 made necrotic strike proc it. Now you don't have to choose between damage+slow or Mortal strike effect. Now you can just spam the mortal strike effect.

DKs simply don't need that "map control" which they get from the to infinity stacking desecration.

I have a few suggestions with the goal to balance this out a little:

1) Make desecration only proc from scourge strike again
2) Set a limit to how many desecrations which can be present at the same time. Maybe 2, with glyph to 3.
3) Reduce the radius of desecration
4) Rework desecration to, instead of it current effect, give the pet's Claw ability a slow similar to crippling poison. This would also work well with the unholy transformation addition to claw.

I do expect DKs to be whining because to suggest a nerf to their slow. Please prove me wrong.