There was a golden era in cinema for Westerns, and after that golden era ended, nobody's been able to resurrect the genre. Many have tried, and all have failed. Unfortunately for United Artists, that golden era ended long before 1980, when they pumped $44m into making 'Heaven's Gate.' This was no way for the movie company that was opened by Charlie Chaplin to bow out, but sadly, that's exactly what happened.
This may have been a simple case of the company believing that everything they touched would turn to gold. They'd made a massively successful war movie with 'Apocalypse Now.' They proved that boxing could be a box office draw with 'Raging Bull.' Why couldn't they bring back the Western with 'Heaven's Gate?' The primary reason was probably that it was a tepid drama, lacking in the kind of action people associate with films that use this historical framing. It made a miserable $3.5m return, and United Artists had to sell up to MGM.