Was C.S. Lewis shrill?

Russell Blackford’s “My most popular posts of the year” post reposts an interesting remark about C.S. Lewis:

Meanwhile, forthright Christians who want to argue publicly for the truth of their views manage to be at least as ‘shrill’ as Dawkins. For example, I’m currently reading Mere Christianity by C.S. Lewis, which I don’t think I’ve previously read in its entirety and have not opened for decades. As usual with Lewis, his style varies between blunt, emotive, self-righteous, and downright snide (I’ll bracket off how naive the actual arguments are). His approach gets a free pass in our culture, but if an atheist wrote in exactly the same way he or she would be roundly condemned.