I think that when that "C" student also shows a resume with a LOT of work experience all the way through school, then an employer would be a fool not to at least consider the application. Dumping every transcript with under a 3.5 GPA is incredibly shortsighted.
What about the kid who worked his way through school doing two jobs? I did: I had a work-study job (in my field) in the daytime and waited tables at night and on weekends: I worked about 40-50 hours per week. My GPA with a double major was 3.48, and I graduated in three years. Would anyone REALLY think that my solid B average wasn't the result of putting in effort?
As for O-Chem, I wasn't a STEM major, but I roomed with three of them during college, dated one for three years, went to undergrad AND graduate school at two of the most well-regarded petroleum engineering schools in the country, and have been in administrative positions at research facilities for half of my working life. EVERY person I know who had to take organic chemistry suffered through it: IME it is the generally regarded as the acid test of any chemistry or engineering school. The guy that I dated in college is now the dean of a major engineering school. He finished his Ph.D at 23, and he held 6 patents by the time he finished undergrad -- trust me, he was no slouch. Even he found O-Chem to be a grueling challenge, and managed to scrape out an A only because of the curve.