It is what it is--I hear this all the time and am so sick of it. Because, of course, in our increasingly totalitarian/Orwellian age what it really means is "It is what they decided it is." A political rendering, I fear, and that in purely philosophical terms fails the "thing in-and-of-itself" criteria that any rigorous interpretation of this notion demands.

The appeal of this quote to me is as you describe - that the greatest degree of rigor in analyzing something should be the thing itself, in the objective and without comparison to something else. So often today, people exhibit laziness in their thinking and make flawed comparisons of things to other things.