Why carry a gun much less draw it, if you aren't going to use it?

I couldn't get past the ridiculous coach scene at the start of this film.

Firstly, the coachman displacing a couple for two dodgy looking guys should've raised suspicions. Then consider the men, who barged onboard without apology or manners and looked decidedly disreputable.

How did Mikkelsen's character (Jon) manage to survive in the Wild West while being such a poor judge of men?

If I was travelling with my family I would've disembarked immediately and waited for the next coach. It's better to arrive late but safe rather than sorry!

Of course, as the scene unfolds we discover these two men are indeed scum but they drop plenty of clues before finally making their move to accost Marie. Their dishevelled appearance, heavy drinking, lack of polite conversation and disrespect for Marie were all warning signs which Jon ignored.

Eventually, after one of them pulls a gun, Jon knocks it out of his hand and draws his own pistol!
WTF?!

If he was carrying why didn't he draw it earlier?
Also, once he drew it why didn't he use it?

These men were clearly dangerous so the lives of his family were at stake. The only sensible thing to do after drawing his own weapon was to shoot them both before things worsened. He didn't do this and so, of course, they got worse. What an idiot!

I stopped watching at this point because if you're going to tempt fate then you'll get what's coming to you...