rebdoniel, it is not merely “good PR and for our gain”.
What you are stating is that our holy sages of yester-year were primitive and unenlightened, and Rav Dov Linzer knows better. This would be funny if it weren’t so sad and exactly opposite of what mesorah tells us.
Your latter remarks, however, that one should act “in consonance with our own social and political metziut” does not contradict this insofar as the specifications of Darkei Shalom apply. This, indeed, may “make us duty-bound to treat all people fairness, kindness and justice”, but only because of the applicability of darkei shalom, whatever exactly that means, not because of some ultra-MO “modernity” trumping the Torah, CH”V.
Your terribly misguided mistake remains, therefore, if you think that Linzer is more moral/enlightened than, lihavdil, Rava and Abaye.