In the end, it’s the people who fight that determine if the thing they are fighting for is worth their lives.
Dying for some lines on the map sounds bad, but if it were only lines on the map, then the people probably wouldn't choose to die for them, would they?
Nobody wants to die, but if someone is ready to give up their life for some cause, then who are you to tell them they can't?
It's the fate of Ukrainians that is at stake and its the Ukrainians that determine if changing that fate is worth the costs of their lives.
I am not going to tell them they can't, they can do as they see fit, of course.
It is a very subjective topic, however. I might save my family even if it meant the death of hundreds of people, or not, it is a moral dilemma for sure. I do not have an answer.
Some people may believe "less people dying" is always favorable.