One can only rely on a twist ending scenario for so long before people become jaded with it.
I know I'm not alone and I've definitely said this before, so forgive me for being boring, but I guessed the twist without even seeing
The Sixth Sense...because tbh it's something I might have considered doing, then discarded as being too obvious.
But yeah, by the time he played the twist ending for the third time I was bored with his schtick, and IMO he completely lost his sh!t with
The Happening and the "run from the wind!" line. (It probably happened before then, but I skipped a couple of films after
Signs.)
But...Alien5 (which is how I styled the title on a long-ago script that I wrote for schizzle and giggles)...
Alien is, without doubt, the best of the lot.
Aliens was a good follow-up, partially because it departed from the first to such a degree; it wasn't just more of the same.
Alien3 (or 'cubed', as I sometimes call it, though no attempt to cube an alien was made until the pretty risible
AvP film) disappointed me greatly when I queued to see it on release day way back when, but has grown on me since - and is actually a bit of a triumph considering Fincher didn't have anything like a proper script to work with/from; he went up a lot in my estimation when I found that out.
Alien: Resurrection...I think there's a decent film trying to get out in that one. It just suffered from
having to have Ripley in it. The star of the first film isn't any of the cast, it's the creature. That applies more or less to
Aliens, too (though Sigourney Weaver might disagree). In the third and fourth instalments,
Ripley was the star with the alien being animated scenery, and that's probably why they're a bit flat. I don't necessarily consider
AvP and AvP:R as canon, but they were junk in any case and can/should be ignored.
So I think there's life in the franchise and Blomkamp should be able to draw it out...but only if he cans Ripley as a character. There's room for Sigourney Weaver, and probably Michael Biehn...but not the character of Ripley. She's rumoured to be interested, but maybe that comes with a caveat of 'only as Ripley'. If so he should walk away, because it'll be crap. It's not the franchise that's played out, it's that character.