That show of forcing the settlers out of Gaza was a self-serving act on the part of the Israeli government. It produced two intended results. It created exactly the kind of sentiment expressed above (those Gazans ought to show some gratitude), and it provided the government of Israel the ability to bomb indiscriminately in Gaza without having to worry about hitting settlers.

The fact is, it was not at all necessary for the government of Israel to remove those settlers (and I submit that they knew this full well). All they had to do was to withdraw the IDF to the other side of the wall and tell the settlers they could stay, but if they did, they were on their own. But had they done that, they wouldn't now be able to use those settlers as a way of drumming up support for their policies.

By the way, the blockade of Gaza started before Hamas started firing rockets into Israel, and is, in part, the reason they started doing that.