I agree with Bobby that Worf just wants to stay with his Captain.
Also remember that this is a brand new crew and not used to working with each other yet. They don't really know what they're doing as a team quite yet. I'd like to think Worf was just trying to prove that he's not a coward and he would stand by his Captain. Probably one of the many junior officers that had tried to impress the Captain since he got onboard.
Contrast this to say the episode "Allegiance", where Picard can easily communicate his intent to the bridge officers with non-verbal signals and get the exact result he was looking for. By then the Captain and the officers knew how to gel together, and knew when it was appropriate to discuss arguments with Picard, which they do, but behind closed doors and not in a position that jeopardizes unity of command (unless drama dictates otherwise of course). It takes time to build this level of teamwork that neither Picard nor the crew have gotten to yet so early in the series, which is why in hindsight this outburst looks so out of place.
It's not until later that the working relationship between Worf and Picard builds up a level of trust that would put Worf into a position to be more opinionated with Picard; enough so that he can say silly things like "Captain I must protest, I am not a merry man!" and know he wasn't out of bounds, as well as the times Worf and Riker would remind Picard that he shouldn't go on that away mission but he does anyway. They knew where their boundaries were.
Of course this relationship is strained in the First Contact movie for this very same kind of outburst, but at the end Picard knew Worf was right.
You should check out how Worf interacts when meeting Sisko in the DS9 episode "Way of the Warrior", and compare that to how he interacts with him as a seasoned Commander throughout that series vs. how he acted with Picard as a junior Lieutenant, it's a good way to see how his character developed. Another episode into Worf's development as a commander can be seen in "Rules of Engagement".