It’s simultaneously correct to describe them as being “more acidic” online, but practically, the penny arcade cartoon seems to fit better.
(It seems unintuitive to me, because I have similar experiences to you! But I’m wondering if my resistance personally to the concept is due to bias…)
In any case, The Penny Arcade comic seems to depict the mismatch hypothesis which the study found little evidence to support:
> Overall, however, we found little evidence that mismatch-induced processes underlie the hostility gap. We found that people are not more hostile online than offline; ...
And while they're not ruling out the mismatch hypothesis entirely, they do offer an alternative which they call the connectivity hypothesis:
> ...Thus, our findings suggest that the feeling that online interactions are much more hostile than offline interactions emerges because hostile individuals–especially those high in status-driven risk taking –have a significantly larger reach online; they can more easily identify targets and their behavior is more broadly visible.
Most people are fuckwads that have to pretend they are human beings out in public due to culture.
Anonymity removes that pressure.
If online discourse is to evolve, merely linking to an irrelevant post from 16 years ago, being presented as gospel, would make for a good case study on why it hasn't evolved.