Yeap, it can get ugly. Which is why I tend to do the space thing with themes on untamed areas of space and resource conflicts. Keep the conflicting elements that make it an interesting story, and jettison the problematic historical elements that haunt the genre.
I once wrote a short story that basically was a mixup with typical D&D set in the Wild West. So you had wand-slingers instead of gunslingers, magical staffs instead of rifles etc. The sheriff was a paladin, though I used the old spelling of Shereeve (Shire reeve).
The Western is a genre and like all genres it's got its own tropes and stock characters and even in the 19th century it never really adhered to what we might call realism. Most westerns are set in areas where civilization hasn't quite taken root because it gives a writer the opportunity to use stock western characters like the gunslinger, gambler, prostitute with a heart of gold, etc., etc. to tell an interesting story. Writers certainly recognized that there were cites that weren't lawless. Most episodes of Have Gun-Will Travel opened with protagonist Paladin in San Francisco enjoying the trappings of civilization including fine dining, playing the stock market, and the opera but would see him travel to other locations where the meat of that episode's story would take place. High Noon subverts this trope as Gary Cooper had cleaned up the town long before the story starts. The Man Who Shot Liberty Valance, an excellent deconstruction of the Western, is all about civilization and community driving out the lawless aspects of the west.
Yep, this is all true. It's not unique to the American western frontier, either...