Certainly, the IDF and Shin Bet should have done a better job of guarding the border, but Israelis are dying now from Hamas rockets flying into Israel in larger numbers than Israel's air defense systems can handle and if Hamas is not destroyed now, Hamas will acquire better missile and more Israelis will die. The only way to stop these missiles and the fire balloons and cross border raids is to destroy Hamas and the other Palestinian terrorists and reoccupy Gaza. This should have been done back in 2008, and what has happened now is proof that it was a mistake not to have destroyed Hamas back then.
If Hezbollah thought it could defeat Israel, it would have already attacked. It is constantly probing and testing Israel's defenses, and the destruction of Hamas will increase Israel's deterrence against an attack from Hezbollah.
There is nothing in any of your posts to suggest you want Hamas destroyed; on the contrary, in all your posts you argue against destroying Hamas. Disabuse yourself of the notion you are being clever.