They do it for the kidz, Celia, those 18ish young'uns who haven't seen the originals or think them 'lame' compared to what they're seeing now, in terms of gore and sex. It's an easy win, for the studios.
I don't know if I feel that teenagers today think that
Halloween is lame compared to the over the top gore that is popular right now. I was too young to see Halloween when it came out. By the time I watched it, I had seen all of Dario Argento's movies. I still liked
Halloween, because it was good.
Gore is a trend that comes and goes. Back in the 70's, there was lots of gore. And after
Halloween, slasher films became rather bloody. When
The Ring remake came out, it was fashionable to be creepy and implicit, the same way that
Halloween was. And that J-Horror thing fell down pretty fast, and now we're back to over the top gore. Halloween isn't really of it's time the way that the original
Nosferatu was.
There are a lot of bad slasher movies that I think could be remade, because they sucked, but they didn't have to.
Halloween just doesn't suck!