After so many dead Palestinians whether combatants or not, compared to the number of killed Israelis, there is no other way? Laughable. Don't buy into IDF propaganda too much.
You have to think about the exploitability of your strategy. Both the IDF and Hamas optimize for a low exploitability number (though, Israel, really, you need to stagger your religious holidays, this is the second time this kind of thing has happened...), having a "kill count limiter" (in a value less than the mid single digit millions) is obviously a bad strategy and is extremely exploitable.