Chaim,
Presumably at the higher levels they were told that the high-tech wall is doing the job. They also felt smart that were listening to hamas conversations, confirming their views. So, they leveraged resources for other priorities, including other threats, that they considered more important.
Could the prime minister also personally walk along the perimeter and review all technical info about new uavs and mine field making? Maybe, but I am afraid there were 100 crazy things happening in Israel that he had to pay attention to. That is where the whole society is at fault for messing up priorities.
So, Israeli government is capable of quickly correcting for the errors and increased cabinet surely has expertise and variety of opinions. Harder to know what wad going on in the peacetime army. If some inferior leaders were appointed over time, IF, it may be challenging to change them in days.
The same wishful thinking of peace dividends happened in other places.. that is why US and EU are scrambling for munitions, Ukraine is going back for months in places they lost in a week.