On the other hand, thanks to people like John Tukey, technical folks can now spare the suit and still be taken seriously. The price he paid may have been worth the benefit we now have.
That's not the same thing. The argument is for choice, not replacement. A more appropriate example would be a single arXiv article written in Comic Sans without detracting from the message.
As for the wider debate, people have pointed out that it's a matter of form vs. function, but there's another aspect, which is intention. If you do not intend to convey any extra information by using Comic Sans, then discussing the font choice is irrelevant. It's only when Comic Sans is used to signify something that the whole form vs. function argument comes into play.
I, for one, am glad that there is a popular font that pisses experts off, Comic Sans is the punk rock of the font world, I hope others will make an impact.