"MOst" is a big stretch. "Some" sounds more accurate.
Just back from a 7k mile road trip CA-NV-AZ-UT-CO-NE-SD-ND-MT-WY-ID-UT-NV-CA and saw extra charge for CC only aq couple of times on the whole trip. Can't think of any gas stations around where I live in SoCal that charge extra for using a CC. (Of course AmPm doesn't accept CCs anyhow, but I'm wary of their gas - my Sunurban definitely runs rougher on AmPm gas than Chevron, etc).