af Wirsen's conservative views and an abundant publication of his literary criticism made him well-known but also provoked opposition, sometimes in harsh words, by his opponents, who represented new ideas with spelling reform and a freer style.
As a critic, Wirsén found a hearing among many educated men, but not much connection with the young literature, and he has become notorious for his many negative reviews of August Strindberg, Verner von Heidenstam, Selma Lagerlöf, Henrik Ibsen and many others.