The concern for the criminals during the time of the crime is misplaced.
What about my concern on who decides they are criminals? What if I don't trust the police to make such judgement?
Condemning them isn't necessary - they're in the act of committing a crime.
A crime which sentence is to be decided by judges. Otherwise we might as well replace cops with snipers.
The relevant question then becomes how much force to apply, as any form of force also places the hostages at a risk. The single relevant question thus is, what is the lower risk to the hostages? The best bet is to look at historical outcomes in comparable situations. This is complex. It depends on the number of hostage takers and hostages, the site, time, the background of the hostage taker, etcetera.
That said, negotiation helps with an ill-prepared bank robber turning hostage taker. 10 hostage takers and 500 hostages indicates a lot of preparation, and strongly points at a lack of negotiation options.
I fully agree on the question, but not on the answer. I simply do not wish the police to have the right to decide how many hostages it's ok to kill in a hostage situation. And giving them the weapons to apply the result of that decision is too close to implying they have the right to take it.
I think everyone reasonable agrees that the decision in such a situation is an extremely hard one. For me, that's precisely the reason to place the burden of making that decision far from the people we use to protect us from common criminals. Because those people are the most biased on precisely the taking of that kind of decisions.