Obviously, it is a generalization. Your generalization encompasses a much greater slice of the female population than college girls and Oprah listeners. Hence, your use of the "on the whole". That means the majority, doesn't it?
As to your "name me a time when women were more ungrateful than today", that's just silly. I don't think they ask that question during census taking so there aren't any stats to prove or disprove the point.
You feel that woman are more ungrateful now than ever before. Fine. You are entitled to your opinion, just as I am entitle to mine, which is, you hang around with the wrong women.
No, "on the whole," or "taken as a whole," don't have to mean a majority, the phrases refer to a generalization about the whole group, and generalizations can be moved by a minority.
As to your "name me a time when women were more ungrateful than today", that's just silly.
No, because the current population of American men are, on the whole, more attentive to a greater variety of women's needs than men in any other country, at any other time, yet the current population of American women, on the whole, have higher expectations than any other group of women.