The "Gentleman's A" harms students in the end. Here's what he says:
In large, introductory courses taken by a substantial cross section of the student body the grade distribution at a typical college or university in earlier times might look something like this: A’s:15%, B’s:25%, C’s:45%, D’s:10%, and F’s:5%. In words, the meaning of the letter grades were given as: A=Excellent; B=Good or Above Average; C=Average or Fair; D=Poor; and F=Failing. Like so many other aspects of American society and culture, things changed very rapidly on the grading front in the period of the late 1960s and early 1970s. It was then that what we now call “grade inflation” got its initial start and experienced its most rapid rise.
Those As in the liberal arts used to be expensive, but now you can get them anywhere. That's why it matters to do math and physics - to show what you really have under the hood.