Probably because war kills people and Wikipedia lists 55 on-going conflicts/wars (albeit many being dormant), and caring about each, like the leftists hates Israel would be a full-time effort.
I condemn both sides for the atrocities committed.
Do you condemn what Hamas did?
If not, you a) don't know history very well (i.e. indoctrinated) and b) unwilling to learn, and c) only interested in propagating hate of Israel.
Do you have solutions?