I have been on this site for a while now and am not attempting to preach to Buff fans. Most people know I am here for a good debate. I am a CSU fan.
As far as the game only being important to CSU fans and not CU fans - I think that is a minority view and simply your own perception. A quick look at the most highly attended games in Folsom over the last 10 years shows otherwise:
2001-2002
Nebraska (53,790)
2002-2003
USC (NA)
2003-2004
Oklahoma (54,215)
Nebraska (53,434)
2004-2005
Colorado State (54,954)
Texas (51,751)
2005-2006
Colorado State (54,972)
Nebraska ( 54,831)
2006-2007
Arizona St. (47,723)
2007-2008
Florida State (52,951)
Oklahoma (50,003)
2008-2009
West Virginia (51,883)
Texas (53,927)
2009-2010
Colorado State (53,168)
Nebraska (52,817)
The games against CSU in Boulder in '04-05 to '05-06 were the highest attended games at Folsom over the last decade and the 2009-2010 ranked in the Top 10. I think the game is clearly very important to a very large section of the CU fan base.