If Hamas ever cared to protect their own civilians they would have evacuated the parts of the city they ware using for their fight. That way all Israeli bombings would not kill a single civilian.
Hamas never cared about the wellbeing of Palestinians, they use them as expendables for their own agenda which is the eradication of the Jews and the distraction of Israel.
I can think of three distinct arguments in response to you:
1) Warfare basics
"they would have evacuated the parts of the city they were using for their fight"... how do you think modern warfare works, like two kids arranging to have their fight behind the bike shed after school?
Warfare comes down to two things: What the two belligerents are capable of doing, and what they are willing to do. Israel is capable of striking anywhere in Gaza with ease. Hamas is not capable of the same against Israel. Therefore Israel fears no retaliation relative to their actions, nor do they fear any retaliation of any sort from the rest of the world. That is why Israel is carpet-bombing civilian population centres, regardless of evacuation zones.
Imagine you are responsible for defending your country against an invasion but you don't have an air force, your opponent does, and the best notice that you'll likely get of an incoming airstrike is a matter of minutes... assuming of course you have any anti-air defences (which I don't think Hamas does). Furthermore, your opponent has effortlessly breached your country's borders.
In that scenario, do you think that it's sensible to concentrate your resources in places where your opponent will have no problem whatsoever in destroying them via air strikes that you have minimal capability to defend against? Or would you make the job of the invader as difficult as possible in the interest of standing a chance of a successful defence of your homeland?
2) Do you think it's the job of the defender against an invasion to take the moral high ground? Especially so when the defender is losing and will inevitably lose that fight?
3) Your criticism of Hamas should also apply to Israel to at least some extent: If Israel cared about minimising civilian casualties, they wouldn't be carpet-bombing civilian population centres with unguided high-yield bombs (which even the US, despite their being very muted in their criticism, has criticised Israel for).
Israel is choosing the means with which they're destroying Palestine, not Hamas. Israel was destroying Palestine by slices before Hamas existed, now they're doing it quicker.