I remember countless episodes where someone got vaporized in a single shot. What show did you watch? In fact, I seem to remember that phasers had multiple settings...one of those being PWNURFACEVAPORIZEWTFNOOB. Realistic Star Trek combat would be very boring, imho.
Space combat: Did you see The Wrath of Khan? They dropped their shields WITHOUT firing! What about the magic torpedo in Star Trek VI: The Undiscovered Country. What about....let's just say that the science teams and engineering teams did a great deal of hacking and inventing crud to solve the shows problem. I suppose, if you wanted it to be like the show, we could shoot at each other for 40 minutes, then one of our BO's would pop up and say "Click here for really cool trick that will own the noobs!!"
But what fun would that be?
It is an MMO, and therefore there is a genre factor to be taken into consideration.
Don't you realize people are playing STO because it's Star Trek? How is STO reflecting this? How is the PVP reflecting this?
Even if you are resorting to the MMO Excuse, now many MMOs that allow 1 shot kills? How many MMOs allow spamming of abilities during combat? Where are our resist values? Where are the buffs that protect us from these abilities? Where is the uniqueness of character types?