Why the ending of Lost still bothers me, even now

In one sentence: because it came out exactly as they said it wasn't.

In a longer series of sentences:

From the beginning of Lost, they kept encouraging fans to try to figure it out, to voice their ideas of how it worked and what it all meant. And from the beginning, people kept saying "it's purgatory" and they kept saying "it's totally not purgatory, it's totally science", and then we get to that last episode and guess what? It's purgatory. Of some sort. And then there's a church and a light and everyone is together except the black guys, and then they all go into the light and it's done.

No.

I will never be alright with that.

Not because it was just a shitty ending, but because a) it felt like a cop-out, like they knew they didn't have the endgame they kept saying they did, and didn't try to give us something better, b) because it was all a lie, and that spoils a lot of the previous enjoyment, c) because it smacked of network meddling messing up a good thing, and d) because, from a writerly perspective, it feels unfinished, and it really only needed a few more seconds of screentime to fix that, and they didn't do it, for whatever reason.

D is the one that most pisses me off. Okay, they can't control network meddling, or writers' strikes or any of that behind the scenes thing. Maybe that messed up whatever they'd originally wanted to do at the end and then they just gave us what should have been a vindication of our cleverness but was done in such a way, after so much denial, that it felt like a lie. Whatever. But the fact that they didn't give us just, like, three more minutes to show what happened on the other side of the light, and prove that it was, all along, science and truth and not supernatural BS, is a permanent thorn in my side.

Ways it would have been better, and which would not have pissed me off:
They go into the light and...

• Get a second chance to make life on the Island work, since now they know, intimately and painfully, exactly how all the mistakes turn out.
• Find themselves watching their past selves, because now they're the whispers that were never explained, and all along, they were trying to warn themselves.
• Wake up on the plane, which doesn't hit the Island, and they get to live the lives they should have lived, but they still know each other and now get to apply the lessons they learned in the closed-alternate-reality of the Island.

Hell, even going into the light and finding out that they're the ones who started the Dharma Initiative at all, at the very beginning of all this, would have been okay--basically, anything that would have brought it back around to something that matters to the show, the characters, and the massive and complicated history of the series, and took it's drift into supernatural and away from science fiction, and put it into a sciency context again, would have been okay.

But we didn't get that.

And I'm still pissed.

We get so many of out shows cut off before the end that I think there isn't a precedent for how weird / SF / F / H shows to actually accomplish an end. And that means when one actually does get an end, instead of just being cancelled, we want it to be good, to prove that things like this can stay good all the way through.

Lost didn't do that, and it felt like a betrayal.