You do realize that in Star Trek, it is the captain who matters? How many episodes is it where the captain who makes key decisions, usually because Starfleet is too removed from the situation to act in a timely manner? You do realize that it was Kirk who threatened to level an entire planet (Taste of Armaggedon) and escalate a war (Private Little War)? Yes, it may be a flaw of the story, but it is not one particular to this episode or to this series.You're comparing raids that were planned up and down the chain of command, authorized by numerous sources, etc... to ONE random captain deciding it would be cool to make a planet uninhabitable.
If anything, this was just really, really bad writing.