Well, Swiss in general differentiate very much between business and private life, and in negotations, especially financial dealings we tend to be very strict/intransigent as you say. I also feel there are huge differences within Switzerland, while I understand why people in Zürich appear unfriendly and cold I as perceive them so as well, it's a completely different thing when I go back to my home village (where people don't know me anymore but still greet with a Grüezi and smile). I think a lot of perceptions here of expats are valid to a degree, it's just you need to learn to overcome the famed aloofness of the Swiss to enjoy their company.