Why?
If you behave in a shitty way in a public forum, you deserve to be called out on it.
This is a community. Outside of the infractions that would be moderated by the mods, in all other behaviour, we're all accountable to each other.
Behave like a sensible poster and others will respect you for it.
Behave like a mindless, rabid platform warrior and get called out for it.
What reason do we have not to call folks out? You're suggesting we don't and just let shit like that continue and the forum end up going to shit? Nah... sorry. I don't think you'll find many on this forum that would agree with you on that.