Yes substantiveness and civility are related. However, making a point in 500 characters vs. 20,000+ characters lends itself to some brusqueness.
I agree however, that lack of civility can undermine your argument. See the very uncivil comments below from Damore's fellow Google employees, including managers. They undermine their argument and literally create a toxic and scary work environment.
I abbreviated the names, but these were all public statements. I just don't want to run afoul of any HN rules regarding naming names.
CB: "You know there are certain "alternative views, including different political views" which I do not want people to feel safe to share here... You can believe women or minorities are unqualified all you like — I can't stop you — but if you say it out loud, then you deserve what's coming to you. Yes, this is "silencing". I intend to silence these views... Take your false equivalence and your fake symmetry, and shove them hard up where the sun doesn't shine."
KB: "I am considering creating a public-inside-google document of "people who make diversity difficult"...which calls out those googlers who repeatedly made public statements that are unsupportive of diversity... Things I'm still pondering: should inclusion on the list require something resembling a trial? should people be removed after some period of time if they start behaving better?
CW: "One of the great things about Google's internal communication mechanism... is that, as a manager, I can easily go find out if I really want to work with you."
KE: "Your reply...ignores the many women Googlers who have expressed the frustration they feel as a result of this. F* off. Thanks for using your real name here, though. Makes it easier to update my spreadsheet."