I was reading Norman Davies' "Europe: A History" when I stumbled upon the mention of the Swiss rebellion against the Holy Roman Empire between the 14th and 15th centuries (pp 404 in my large paperback version).
I don't think he really explained why these men tried revolting against their extremely large and powerful liege state just to be independent and I couldn't really find anything about their motives online either.
I'm no historian nor history student. I'm just a normal history buff so this was really confusing to me.
This old answer should answer your question.