Sometimes preachers declare that style is always secondary to content in preaching. The preacher should make sure that the people are receiving good content, and if the people are exposed to good content every week, the people will be weaned off of the use of emotion which will cloud the mind. At least that is what some would argue. In fact, if you do a good job, so the argument goes, you can deliver the sermon in a calm objective lecture style and it will be just as effective as if sweat were dripping for your brow as you yell the sermon at the top of your voice.
Now I would agree that vocal volume is not the only way to increase intensity, but I would strongly disagree with this attempt to privilege calm preaching over fiery preaching. In addition, I would not want to say you must be yelling to be a great preacher, but emotion must be a part of real preaching if it is to effect the whole person and not just the mind.