As you can see Erinn, we devotees of Nietzsche might likewise be characterized as "purists."
We try to remain pure in seeing the complexity of philosophical dilemmas such as the nature of "reality;" rather than accepting some simplistic expression of common (all-too-common) sense. We wish to remain pure in refusing to reduce to straw men the philosophical giants of the past three thousand years merely as a vehicle to our own self-aggrandizement. And, finally, it is to be hoped that we remain purists in our modesty, which always asks that we look behind our truths for reasons pro and con. I must wonder if this latter search for reasons is not the essence of being "reasonable" (if not of rationality itself).
"...the great majority of people does not consider it contemptible to believe this or that and to live accordingly, without first having given themselves an account of the final and most certain reasons pro and con, and without even troubling themselves about such reasons afterward..." The Gay Science I-2
My, my, my to dismiss Nietzsche -- by merely designating him as an "irrationalist" -- is truly an attainment of the most pure form of superficiality. My hat is off to the mighty "philosopher" Ayn Rand as the goddess sublime of the egomaniacal simplification.