A good question.
In the 1990s, the first suicide bombings were carried out by members of the militant Palestinian group Hamas. According to data from the University of Chicago, 114 such attacks, in which the assailant blows himself (or herself) up, have been carried out in Israel since 1994, resulting in the deaths of 721 people (including the perpetrators).
In 2007 Hamas controlled Gaza after open fighting with it's rival political group Fatah.
Smai Abu Zubri, spokesperson at the time for Iran-backed Hamas claimed it was a “second liberation of Gaza from the collaborators”. Hamas made clear it's avowed goals which were the destruction of the State of Israel.
The Israeli Prime Minister at the time, Ehud Olmert suggested that the West should give “serious consideration” to posting a peacekeeping force in Southern Gaza, to stop weapons reaching Hamas via Egypt.
This was not implemented.
In Dec 2008 Israel commenced Operation Cast Lead – a 3 week military campaign aimed at stopping rocket fire from Gaza.
In Nov 14 2012 Israel launches Operation Pillar of Defence, an eight-day military campaign sparked by an intense round of rocket fire from Gaza aimed at Israeli civilians.
In July 17 2014 Israel launched Operation Protective Edge, a military campaign that included a ground invasion aimed at destroying Hamas tunnels used to smuggle weapons into the coastal enclave and launch attacks against Israel.
So, the dismantling of all Israeli settlements in Gaza and the relocation of thousands of Israeli settlers did not bring an end to violence emerging from the coastal territory and aimed at Israeli population centres. (The Israelis even exhumed their dead and removed Jewish cemeteries)
The Israelis further argue that violence against Israeli civilians is not intended to bring about peaceful coexistence, citing as evidence Hamas’ longstanding refusal to recognize Israel’s legitimacy and right to exist.
In 2016, Israeli Prime Minister Benjamin Netanyahu summed it up saying that terrorist attacks “don’t come because of [Palestinian] despair and the frustration over the inability to build. They come because of [Palestinian] despair and the frustration over inability to destroy.”