The Power of Swear Words.

No one reacts to the words themselves, they react to the intended disrespect or nuanced implications of the word.
They do not get emotional because the words themselves are emotional words, but because the context of them is.

This is true within the confines of a single culture.
However, when people of different backgrounds converse, one might attribute more force/disrespect to any given word than the other.
Examples: political correctness (I'm not a "girl", I'm a "woman"!), religiousness (is "god damn" a really bad curse or a mild one?), and just plain vocabulary (the examples given above of people who use the 'f' word as filler even when no particular emphasis or insult is intended).