Despite this failure Israel has to continue developing its attack and defense systems since it has had many past successes.

Arrow 3 is still in the development stage and there will be some trial and error until the bugs are fixed and there will be successful tests and failures and its unfair to expect to much to soon. Much better that the tests should all fail now getting some bad press than it being rushed into service and it failing in a war.

Basic physics says that anti-missile technology will fail most of the time. Even "very accurate" surface to surface missiles have limited accuracy (typically about 30 meters), so how likely is it that two missiles, each doing well over Mach 2, are going to be able to get within 30 meters of each other, especially since it takes only minor course corrections for the incoming missile to avoid the anti-missile. The ONLY thing more wasteful of Israeli and US war toy dollars is the F-35 non-fighter. Any Israeli that is counting on anti-missile technology to keep them "safe" is TOTALLY DELUSIONAL.

Can't even assemble the parts and components they get from US to make the damn thing fly.

Its no big deal because everything will work out in the end, or so was seen on a crystal ball.