Hamas did attack a festival and fought people they encountered there (police and army). Hamas did kill some Israeli civilians. But Hamas being an imperfect resistance group is enough for liberals to solely focus on condemning Hamas and showing support for an apartheidsregime that has been committing genocide for decades now.
If they were alive during the time in which the native Americans fought back, they would've sided with the colonists. They would have sided with apartheid South Africa. They would cheer on the destruction of Vietnam. Because they can't think further than 'killing is inherently bad, and my government says to hate you'.