To answer this, you might begin by studying the story Crane wrote as a kind of analogy for the so-called Old West itself: the happenstance meeting of several unlikely people all together for reasons of their own who wind up, first, deeply affected by one another's actions and, second, responsible ...
To answer this, you might begin by studying the story Crane wrote as a kind of analogy for the so-called Old West itself: the happenstance meeting of several unlikely people all together for reasons of their own who wind up, first, deeply affected by one another's actions and, second, responsible en masse for the preventable death of one of those people. An examination of the history of the Old West will show a very similar makeup, as hundreds or even thousands of people of all origins and ethnicities traveled West in North America to explore, survey, and settle that which had been previously unknown. It is unthinkable to imagine that so many different people could cross paths on their journeys without either affecting others or being affected themselves by others' actions and decisions.
In short, the "Old West," all stereotypes aside, looked a great deal exactly like the scenario Crane crafted in "The Blue Hotel": strangers arriving in a land previously indwelt by others (Scully and his son, for example) who had been there before (for however short or long a time), only for those incoming strangers to wreak tremendous havoc upon the "native" people (of sorts), as do the actions of the Swede, who is at first paranoid and then increasingly aggressive and determined to have everyone else present shore up his own narrative and viewpoint and eventually responsible in no small part for his own regrettable demise.
Simultaneously, the conversation between the Easterner and the cowboy at the conclusion of Crane's story might indicate to you the likelihood that the Swede was not, in fact, necessarily the only problem, or the problem at all, since the Easterner wisely holds that "[e]very sin is the result of shared effort." In light of that remark, which might prove to be a worthwhile thesis upon which to explore Crane's story in your analysis, it follows that everyone present shared some of the fault for what ultimately happened, even if some of them (the cowboy, for example, who protested his own innocence to the last) refused to acknowledge it. Such may also be said for the Old West with its creation and its eventual vanishing: that as many different people as it took to create the idea of the "Old West" in the first place, it was equally the work of the same people to tear it apart again, with or without a personal stake in the outcome.