No, I think you should reflect a bit more. If they have to sacrifice a few settlements in Gaza today to be able to create 30 times more in the West Bank tomorrow, it makes perfect sense. And, it doesn't mean at all giving up Gaza for good: in fact, soon after that, they closed Gaza under a total siege that lasted 20 years, until they found a good excuse to retake that one too.
In chess you sacrifice pieces. Only a really naive player would think "well, if he sacrificed that piece, that proves he doesn't want to win the game".
Israel’s disengagement plan was a huge topic of internal debate before being approved by the Knesset. Arguments for it were about demographics and security. I don’t recall any proponents of the plan saying that it was a temporary measure (though some argued Israel could easily regain control if required, as a backup), so that seems like a farfetched explanation.
Indeed, Wikipedia gives security challenges and demographics as the main drivers:
[WP] According to Sharon, the disengagement plan was aimed at addressing Israel's long-term security challenges by shifting the country's resources to focus on strengthening the areas that "will constitute an inseparable part of the State of Israel in any future agreement" with the Palestinians.
So this was the immediate motivation: to give up some small, expensive and challenging settlements to focus resources on occupying more land in a more important place. Notice: not an ethical argument, not a peace offer. No. "Let's use our resources to take from the same people more, better land somewhere else."
And of course Israel managed to spin this with the US in such a way that basically they got a green light to settle as much as they wanted of the West Bank.
There have always been people, in Israel, who had the long term goal of annexing the whole "Greater Israel". They might not be a majority, but that doesn't matter because they have no meaningful opposition, as most Israelis are indifferent to Palestinians and to the idea of equity and justice.
And what's happening now is clear. There's no military goal whatsoever to the ongoing flattening of the Gaza strip. The purpose is only to make the place unliveable and to kill time in wait for the final green light to the ethnic cleansing.
