Point taken, but remember two things: in almost every post-accident CVR transcript, nobody's cursing or yelling... everything's hunky-dory until things go awry. That includes things going wrong due to pilot error. Often the opposite is the case: crews getting jovial and a little too relaxed often leads to disaster.
Back in the "bad old days" of commercial flying, captains were generally rather- uh- colorful... and aside from weather and mechanical problems, the safety record was pretty good.
If this guy was flipping out completely, I might be alarmed, but...as for cussing at a passenger, well, that's a Public Relations problem, worthy of discipline... but not a safety problem.
The other thing to remember is that when the police are dragging body bags out of the house next door, the neighbor being interviewed by the media almost always says "I don't get it- he was so nice, so quiet... never heard him raise his voice once..."
