Are Latvians really rude?

During the intensive courses of the Latvian language I regularly find out new things about my mother tongue. For instance, last year students told me that Latvian contains a lot "Sh*t words". I was really surprised and could not understand why they say so. Everything became clear when they told me about their trip to Riga Central Market. In Latvia as in any other country, people don't use correct grammatical forms in their everyday speech, thus what is initially as "šis" or "tas" (this or that in translation)in everyday speech sounds like "šitas".