If anything, Twelve Angry Men is more about the power of an individual to turn the tide. Even without Juror 8, however, it would be unfair to say the rest of the jury is misusing their power. With the exception of a few jurors who are clearly biased, the others are all honestly convinced that the boy is guilty of murder.
After all, on quick review, the evidence seems overwhelming. There is even an eyewitness. Is it misuse of power that the rest of the jury wasn't as attentive as Juror 8? It would be an impossible requirement to demand that all jurors would completely understand the meaning of the evidence. That is the desired outcome, the ideal proceeding. In real life, that is presumably rarely the case. The people who sit on juries are human. If they don't have the knowledge to see through a clever trick or a masterful lie, there is nothing to be done. That is the risk of that sort of a judicial system.
The question of misuse of power comes from the jurors' reluctance to discuss the case, but even there the same argument rises. With the eyewitness, with the murder weapon—to most of them, the case seems very clear-cut. The whole drama takes place only because Juror 8 uses his power to delay the verdict. Since the judgment needs to be unanimous, an individual has a great deal of power. Juror 8 uses it to make sure they properly consider all of the "obviously damning" evidence.
Certainly, the jurors who are clearly voting "guilty" because of their prejudice or personal reasons misuse their power. They try bullying, rushing, insulting, and other methods to get their way. The drama, though, puts emphasis on those who try to deliberate, and most of the jurors are shown to eventually consider what they previously thought was an open-and-shut case.