If you only criticize civilian casualties when Palestine resists, then your concern isn't civilian casualties. Your concern is Palestine resisting massacre.
Where are the Palestinians resisting this behavior. No society would tolerate a neighbor doing that.
They aren't showing you those, because it doesn't fit the narrative they want you to adopt.
They also didn't tell you that the concert just happened to be adjacent to a military base and to anyone who saw it, it was pretty apparent the military base was the actual target.
Did you read the article you are sharing? In that same page is written:
There were no images to suggest militants had beheaded babies -- a particularly explosive accusation that first emerged in Israel's media and initially confirmed by Israeli officials.