I would agree for the most part about humor and the pulpit. To be sure it is mostly the case that those given to the preaching of the Word today use humor in an unacceptable way which detracts from the sobriety of the means grace which God has designed to bring God's truth to a congregation. However, having said that, Scripture itself does include humor, sarcasm, etc., which should not be avoided when it is part of the passage being considered. One example that comes to mind is when Elijah was dealing with the prophets of Baal on Mt. Carmel (1Kings 18:19ff). Consider the following:
1. Notice how Elijah mocks the beliefs of Baal worship by pouring copious amounts of water upon the wood. Baal was allegedly the god of nature who brought rain, etc. And so, Elijah pours water on the wood mimicking what Baal was allegedly able to do but in an exaggerated way... "Hey, you worship the god of rain do you? Okay, fine. Let's pour some water on this wood, NO..., I'll do better than Baal and so how about more water and even more water, yes... and even more water until it is flowing off the alter unto the ground and then I'll show you how much more powerful MY God is.

2. Notice his derogatory remark after the fanatical antics of the prophets of Baal had failed, "Cry aloud; for he is a god: either he is musing, or he is gone aside, or he is on a journey, or peradventure he sleepeth and must be awaked." His sarcastic (humorous remarks) resulted in these prophets to do even more bizarre acts, e.g., cutting themselves, etc. Pay special attention to his even rude suggestion that Baal was perhaps preoccupied on the toilet (cf.
musing).

So, I think there is a place for humor in preaching where the Holy Spirit Himself has deemed it good to include it in the Word.
In His grace,