Huh, for me it's the opposite. People have told me they appreciate my calm and how I'm really good with crises. Then again, I'm a far cry from the stereotypical monotone, I speak very expressively (in terms of emphasis, inflection and so on) and love public speaking. The worst I've heard about this subject is that I apparently almost never smile - laugh, yes, and often, but not smile.
In fact, others are clearly bothered when I do express emotion, because it's usually in a rather immature way.