Agree. Slide to the base, not "slide at the fielder so he can't get the throw off."
If I was commissioner I would come out and say "Look, I know it's ambiguous because this is how it's always been. Playing hard, and all that. Most baseball people don't see anything wrong with Coghlan's slide. Guys have been taught over and over that that's how you play the game, but we're going to change that. From now on, slide to the base. If it looks like you're sliding to take the other guy out, both runners will be out."