If blowing up a ship that with 99% probability had nothing but innocents on it is considered "doing his job", then the world government deserves to fall.
Ok, let's assume that in the eyes of the World Government, Ohara scholars is the equivalent of a world-ending plague.
Now, would you or would you not kill a ship of people to end this plague?
It's that simple. The argument isn't whether or not the World Government is right. The argument here is whether or not Akainu is being "bloodthirsty". I have to say yes, he is, but not in the way that most people are implying. In the eyes of the World Government, he is doing no wrong.