The origin of the phrase "to go Dutch" is traced back to the 17th century when England and the Netherlands fought constantly over trade routes and political boundaries. The British use of the term "Dutch" had a negative connotation for the Netherlanders were said to be stingy. To "go Dutch" implies an informal agreement that each person will pay his or her own expenses during a date.

Don't think about it in a cold logical way. English (and England) has a history. :) This explains it pretty well: http://www.youtube.com/watch?v=Bq9_3bZ8emQ

Because Dutch folks are known to be extremely frugal or stingy. That 's why it's used this way. There are quite a number of jokes or idioms that are about the stingy Dutch people. Quite an interesting idiom for sure.

This is because the English sneered at the sensible frugality of the Dutch as being stingy! Then there is the "Dutch baby", "the Dutch uncle", "Dutch courage", "Dutch oven", "Dutch cap", "double Dutch", "Dutch comfort", "Dutch metal", "Dutch doll", "Dutch wife". Most of these terms come from the disdain of the Dutch by the English during the Anglo-Dutch Wars in the 17th century!