I don't buy that generalization for a second, and I think it sucks that any adcom would. My General Chemistry class at ECC took the ACS standardized final, as did UB. Our average blew theirs out of the water, without any curve. My Organic Chemistry professor teaches the course at both ECC and at UB. Again, sans curve, our average on tests blows theirs out of the water. And it's not even freakin' close. On every test so far, our average, pre-curve, has been at least 30-40 points higher.
I have also heard that schools look down on students at community colleges, but given that set of data, it seems odd to me that adcoms would think that community college somehow lowers the bar. These are the exact same tests, so throw the "CC tests are easier" hypothesis out the window. These are pre-curve grades, so throw the "less competition on the curve" hypothesis out as well. And, obviously, it's the same material, taught from the same book, by the same professor, so the "weaker curriculum" reason is gone as well.
Maybe my community college is the exception, but from being there, I can tell you that the students aiming for pharmacy aren't there to screw around and backdoor the system. They work hard, and they succeed because they're in an environment conducive to their success. Yes, there are CC students who are merely rejects from a 4-year school, but honestly, most of them are business, liberal arts, english, or some sort of "soft science" major. How many of those people would last long enough in pre-pharm coursework to get close to even sniffing the air at a pharmacy school anyway? Don't underestimate the power of Gen. Chem. to weed out students.