Yeah, I don't think I would've liked this much either.
That ending for Kylo/Ben would have been bleak as fuck. Han and Luke (to an extent) died trying to reach out to him in the previous two movies, but in the end he has to be put down like a rabid dog? THAT would've been the end of the Skywalker family? Nah, no thanks.
TROS has big problems, but Adam Driver as Ben was such a highlight, and I'm glad we got that at least.
This script does start off a lot better than TROS, and has two big positives in its favor (Rey Nobody, more Rose). Those alone help it feel more like a continuation of TLJ than TROS does. I also like that Force Ghost Luke sticks around to try to bring Ben back, whereas in TROS it feels like he gives zero fucks about his own nephew. Though Ben is "extinguished" in this script, so that make Luke's efforts feel futile.
I also like how it brings up the cyclical nature of the light side vs dark side and masters repeating mistakes. I thought IX would bring that idea full circle — how will the new generation fix the mistakes of the old, prevent that cycle from continuing, and bring balance? Neither this script nor TROS really resolve that, but I guess this script at least brings it up?
Kylo killing Rey's parents makes no sense. And it still feels like the story jumps around a bit too much here.
In any case, even though some of the stuff here is better, I doubt Trevorrow would've executed it well. JJ, for all his faults, is still the better director between the two.