I must agree with Kevin on this.
If we allow ourselves to be brought down in our entertainment because of supposed flaws in logic or reality, then we might as well not go see anything remotely ficticious, be it science, fantasy, criminal, or other.
That is why I am a strong proponent of "Logic and physics always give way to dramatic storytelling."
I was darn near moved to tears when George Kirk made his sacrifice so that his wife and son could escape death (something for which James T. would become notorious for....well...until he met Soran
If Captain Robau had not acted the way he did, then we would've been deprived of a truly great scene. Sure, Robau was likely a good captain, but we have no real vested interest in him, and in his short screen time, he hasn't given us much to be sympathetic about...save for his quick demise....but, that death served a purpose in the story.
If Robau had stayed aboard the ship, the only way he would've been even remotely given any sympathetic nod would be for him to have remained aboard to pilot the ship to its fiery end when the auto-pilot went out. But, still, the ending of that scene would not have been near as compelling. He could've said a few lines that may have further endeared us to his character, maybe even said something to George that would've been legacy bearing, and something for George to pass on to little Jimmy T., but still, even his sacrifice just wouldn't have fully registered with us on any lasting level.
Meet Commander (now Captain) George Kirk. Command was thrust upon him by Robau in an act of desperation. Kirk did not desire command...at least, not in this manner. You could see it in his face as Robau left the ship. (You could also see a look of regret, as if he was almost certain he was never going to see Robau again.) Already, that expression alone endears us to George Kirk. But, also, when we hear: "You're Captain, now, Mr. Kirk." something clicks in our minds. (OK...this guy is a Kirk....this must mean something good.) Name recognition, for good or ill, goes a LONG way.
We clearly see that Kirk loves his wife, and does his damnedest to get his wife, and soon to be born child off the ship. He was apparently even supposed to be able to get off duty (during what should've been peacetime) to be with his wife and newborn child at the time of the child's birth. Kirk does what a good captain does, and orders everyone off the bridge and to the escape pods. Seeing that he is indeed the last person moving for the turbolifts, Kirk turns around to activate the auto-pilot. The computer informs him that auto-pilot is off line. It is clear on his face that if he does NOT remain behind to manually pilot the ship in, no one will escape the wrathful barrage of torpedoes the Narada is unleashing. His wife and child, not to mention hundreds of others, wouldn't have a chance. So close! Dammit, so close to being able to be with his wife and child! So close to being able to share a common bond with his son, of a life and death experience that would be a part of their lives forever. However, he stays in constant contact with Wynona, his wife, to comfort her, and reassure her, at least long enough to ensure that she DOES get aboard the shuttle, and then ensure that the shuttle DOES take off, regardless that he is not there. Then, as the shuttle speeds away, and the Kelvin rockets toward fate with the Narada, we hear a baby crying, which jolts Kirk somewhat back to a more peaceful time. So endearing, and indeed so serving the purpose of dramatic storytelling is the brief little debate George and Wynona have over what to name their child. We see a tear form in George's eye as he desperately tells his wife that he loves her so much....he wants to tell her as many times as he can in those last seconds....and then, he is gone.
In the few short minutes, we come to know George Kirk really well. We don't want anything bad to happen to him. But he selflessly gives his life for his crew, and for his family, and we are moved by his sacrifice. It is a few minutes that is an emotional rollercoaster ride, which serves as a kickoff of the life of one James T. Kirk.
This is where dramatic storytelling serves its purpose. We are given characters to care about, even if it is for a brief time. Even if starship captains make the mostest stupidest (yes, I'm deliberately using bad English here) decisions in the history of the galaxies, it is our caring for these individuals (our nature as humans being) that allows us to enjoy this partiicular "what if" out of a list of what if's, and accept that what's done is done. Robau is gone. George Kirk is gone. Wynona and Jimmy T. live on. Life arises from tragedy and sacrifice. A new legend will be told. Even those who were not at all familiar with Trek were moved (some to tears) by these few minutes of establishment, because nobility resonates with humans being. And somehow, even the uninitiated know that this nobility will be borne along with James T. Kirk.
That is why dramatic storytelling works. It throws computerzed logic and physics out the window, and appeals to our human side...the side that tells us to enjoy what we have, and to relish what our fictional heroes may have, or regret what they have not, even as a result of some of the mostest stupidest decisions in the universe. Dramatic storytelling appeals to the human factor. We, as humans, are flawed. So who are we to judge the flaws of the ficticious?