They beat up on Grambling -- one of the weaker FCS schools -- so that doesn't mean much.
They then beat SDSU, but they are 2-3 on the season having lost to South Alabama. This is not one of the good SDSU teams.
They beat Texas, after Texas shanks an extra point. While Cal deserved to win the game, Texas is not a good team (as TCU showed yesterday).
They beat Washington, which may be their best win of the season, though Washington actually looks like they will give Washington State a fight for the worst team in the PAC.
And most recently they beat Washington State.

I understand Cal being ranked because they are 5-0, and pollsters often rank P5 teams based on their record alone. Having said that, Cal has done nothing, at least to me, to show they deserve their ranking. Nor have they shown any reason why it should be thought they can beat Utah.