The only reason to keep rehashing the original is in order to have the big lump in it. Otherwise story wise it makes no sense to have the same model of terminator over and over, getting older and older.
They think people want to see him as the terminator, more than they want to see a good film. They are right to a degree, unfortunately.
Cameron was right to walk away from this whole thing. He said all that had to be said, he really did finish it with an underline and full stop with T2.
Thinking about it though, I'm not sure what else can be done story wise to take it forwards, other than rehash it.
We know what happens you see, we know there is a war, we know Conner becomes the leader and wins the war. How is that going to be interesting to see, ooh just seeing it played out and depicted, nah boring. As evidenced by how dull story wise Salvation was.
There is no tension at all in watching Salvation, any time there is any kind of action or supposed danger, it evaporates because you know Conner will live, you know he will win the war and send his father back to save his mother from the terminator. If he doesn't we wouldn't be watching what we're watching.
The only way it works is if you keep having terminators being sent back in time to stop the future. That's the story, that's the appeal, its a time travel scifi action adventure thriller. There is suspense if we don't know whats going to happen, if they are changing the future. That's why T2 works.
If they wanted to be bold, to make it work, they would kill Sarah Conner in the first 10 minutes. Then we don't know what the fuck is going on, how did it all play out, how are we still here with terminators in the past if Skynet managed to kill her. And for the love of god ditch the big lump and get a new terminator.