"Tina didn't want to sleep alone"... and that's why she had to DIE. Horror's condemnation of pubescent sexuality is something I'm quizzical about, since it eagerly teases its audience with nubile ladies and then takes rather sadistic pleasure in ripping them to pieces. Perhaps the intention is to reveal the dangerous qualities of aggressive, domineering male sexuality -- putting the audience in the place of the helpless. But there is a voyeuristic tone to some of the scenes that compromises the force of the message, but I'm thinking of Halloween more than Nightmare on Elm Street.
The latter gets to the heart of the issue by dealing with the power of fantasies and dreams directly (Blue Velvet is pretty much about the same thing). Krueger has chosen to abandon reality and realize his most selfish and antisocial desires. He is also a symbol for middle class fears of the feral working class (he likes to hang out in a factory). The hero has to learn how to identify what's real from what is imagined, and conquer it (the booby-traps as a symbol for the mastery of nature?). But ultimately, we cannot escape the fact that we are prisoners of our senses and what our imagination does with the information they give us. We make our own reality, and we can't always control what goes on in it -- Freddy can always sneak out and get you if you're not careful.