Your premise is flawed. Do I want the innocent to die? No of course not, don't be daft. But making the guilty clean up the mess runs afoul of all sorts of international conventions (most notably the Geneva one). It's shitty but at the same time it also prevents Ukrainian POWs from being sent into an Ukrainian minefield for clearing (prevents used here to mean: should not happen but russia is a smelly country so they would totally do it anyway but it is not allowed.)