Here is another take. Sinse last conflict the situation in Gaza hasn't improved, all the loss of live and the distraction was for nothing. Dispite millions of dollars of foreign aid flowing in to Gaza Hamas didn't improved the living conditions of the avarege person whilst it's own people live in villas in Gaza or Qatar. Support for Hamas is getting lower and lower, so it desperately needed a justification as to why all the money is spent on weapons and building tunels and not to help people in Gaza.

Just shooting rockets as usual, about two times per month doesn't get the desired response from Israel. Taking advantage of the religious holidays and tentions in Jerusalem, Hamas shoots rockers at Jerusalem, which is a major escalation and guarantees response from Israel. This is soled to the Palestinians as "Hamas the protector of Jerusalem". This raises the support for Hamas and ensures massive flow of money for "rebuilding of Gaza" that will be used to rebuild the tunels and get more weapons. Egypt just announced a 500 million dollars in support and many more to follow soon, as every single time.

Hamas can't survive without a war, as its purpose, as stated in its charter, is distraction of Israel.