No, I do not underestimate it, I am even one of those people you refer to, as you can see in my comment to Haberjr.
Nevertheless, I have also seen comments from people here and elsewhere who stated categorically that they do not care for WYSIWYG, some have even asked Licat not to make it default.
So, I would say I am realistic: yes WYSIWYG is important for many people, but I do not ignore the others either.