That may be true, however, when facing an existential crisis, Bibi and Ya’alon are still opting for peace through negotiations, while giving lip service to fighting Hamas by using air power. The extremely limited ground incursion was halted before it became truly effective.
Hamas has now had time to rearm with more Iranian weapons - via the Sinai tunnels which are still open; to drive people from their homes along the Gaza border - with mortars and short range rockets; to declare victory over Israel; to come up with a defense against the Windbreaker system - which Hamas had no counter.
Point is: the suicidal mentality still remains strong - potentially strong enough to create a war of attrition which Israel cannot win, and thus, commit suicide.
Meanwhile, we face a similarly left-driven suicidal regime here in the US which fails to recognize that war has found us (since 1979), and we will shortly be facing the same or worse threats as Israel - see ISIS claims to have found Saddam’s ‘lost’ WMD.
If Israel goes into downtown Gaza with whatever force she chooses, it will mean the loss of ~400 soldiers and the occupation guerrilla war with more losses. This is something that Israeli society, being as Western and forward thinking she is, is unwilling to accept. Israel does not want massive losses and that is the SOLE reason we say an air campaign. Who wants to lose hundreds only to give it all back again to the terrorists? This is Israel's history:
Defensive War
Victory
Withdrawal To date, Israel losing 67 soldiers is an American equivalent of about 2,400 soldiers within a 6 week period!