Deadwood is a gritty, nasty show. It never stays in the same place too long. Each show takes place over the span of 24 hours in the camp, and usually after a block of shows, things have noticeably changed in the camp. The cast, crew, and writers do an admirable job of making the town _feel_ like it's in transition, not just tell you that it is.

I've found I got used to the dialogue, but my threshold for the f-word is probably a little higher than yours. However, there's some wonderfully clever wordplay and monlogue construction going on, and I don't know as the show would work as well without the cursing.

Wikipedia on the use of profanity in Deadwood