Let's not forget that earlier, Heather's hit by a car on the freeway trying to get to Dylan before Freddy does. Does that stop her? NO. That is the basic definition of a Mama Bear.
Shortly before stabbing him in the groin, Heather's response to "Freddy" coming at Dylan is to scream "FUCK YOU!" and punch him right in the face, bowling him over.
Dylan is a brave little trooper for managing to think relatively well on his feet considering what he was up against, and having the guts to stab Freddy on two separate occasions in the finale. The second one is the final blow that lets him and Heather push Freddy into the furnace.
Heather's babysitter, Julie, gets another one. A couple of nurses are attempting to give Heather's son an injection that will help him fall asleep—something that they absolutely do not want to happen considering what franchise this is. Julie clocks one nurse in the face, knocking her clean out of the room, and chases the other one out with a syringe. Of course, Julie still dies not five minutes later. But hey, it was still pretty badass.
The fact that this Freddy brings back the original's menace and overall creepiness, with none of the camp. Whatever jokes the bastard makes are not meant to be played for laughs.
Englund's performance. In the first movie, Englund was little more than a generic slasher villain with an odd gimmick and look, and Englund had surprisingly little screen time. The final act of this movie rests largely upon his shoulders, and he's more than equal the task. Seeing the same man who normally plays Freddy as campy killer spouting Bond One Liners transition to a truly frightening nemesis who's quips are absolutely not Played for Laughs leaves no doubt about Robert Englund's acting skills.