It's no western theme or anything like that. It's human nature. When you encouter 2 games of a similar genre, chances are you'll tend to lean gradually toward playing one of those games exclusively over time, as opposed to giving both games equal attention. And I've leaned toward playing GR2. Ideally, most of us would like to do the latter and keep/play both (GR2 and Halo 2 in this case), but it just doesn't work out that way due to various reasons.
Kruza