I think the article and the comments are wrong. I prefer things to be a little bit fun, and I suspect most people in the real world do too. It's definitely better than some PR driven corporate speak. Now if you want to say that the errors should be more detailed, then sure. But don't punish me with a drab error message when I'm already annoyed about the thing not working.
And again, it's all subjective. I suspect most people in the "real world" (whatever that means) do not actually find it fun, hence the vast majority of professional writing in other industries not having any emojis.
Lack of emojis doesn't mean PR driven corporate speak either, and in fact both are on same level of equivocal communication.
Why exactly? The entire point of the article and the many comments here are about how subjective, useless and usually aggravating it is.