Could it simply be that the Israeli army was a) overconfident because they had (some years back) smacked so many Arab armies around and b) rather out of practice when it comes to large-scale operations? They may also be seeing of the problems that can result from an army based on conscription - constant turnover leads to shortfalls in training and can also result in equipment being poorly maintained.

I also tend to agree that Israel has come to rely too much on airpower. Airpower is a good "sell," since it doesn't put many of your people at risk and does look neat when replayed on television, but it simply isn't the right answer in many situations. It is a great supporting component, but over-reliance on it can lead to problems.