You didn't quote a number, but I'm sure you heard the figures here and elsewhere. Of course the figures matter. The high percentage was supposed to serve a purpose portraying Israel's retaliation as reckless, using indiscriminate shelling of civilians. Civilian casualties lower than those in conflicts involving Western armies would not have served the purpose of demonizing Israel.
Gaza is predominantly populated by civilians. Still, there is nothing Israel could do but return fire when it is being targeted from schools, mosques and hospitals. Thankfully, civilian losses here are low, and as you well know this is not down to the Palestinians' moral standards.
Again, the percentages matter, together with brushing aside the fact civilian installations are used by the Palestinians to fire at Israel. They matter because they incite people to think Israel is as bad or even worse than its enemy.