Even though the people largely supports their agenda, an action that targets three people but affects 2,700 people as collateral damage would not pass by their parliament.
I understand your point but synecdoche is the oil on the gears of discourse. This required a lot of people's involvement, from those issuing the orders to technicians at the bottom of the chain of command. It's not Netanyahu's cabinet that did the work of placing explosive charges in thousands of compact devices and then repackaged and shrinkwrapped them.
Obviously once could refer to the 'Netanyahu regime' or some other more specific term, but then someone else would complain that this was a mendacious mischaracterization of the country's political system or suchlike. To the extent that civilians there don't with to be identified with their political leadership or take on the moral responsibility for its decisions, they'd better step up their efforts to topple the government by means of a general strike or some other time-honored method.
I do think we can hold Israel as a country responsible. But what we can't do is blame Jewish or even Israeli people in general. Though I don't see anyone doing this. The current government is always quick to draw the antisemitism card when being criticised but I never see anyone actually doing that.
It's unknown how many were family members of targeted individuals, and whatever the number actually is, it'll be misreported.