The internet is a place where usually people can state their views openly. That is happening. However, what's also happening is people find his views and comments disgusting and they're commenting on it. Totally within their rights to do.
And it's not as unthinkable as you say at all that an individual or organization would attack others for what content they create. Since there has been an internet there's been people who attacked others for their content. I'm not sure what internet you saw 20 years ago but it wasn't the same I saw.
rotten.com? stileproject? goatse.cx? were there even other sites 20 years ago? The Smoking Gun? When did Cryptome/Cartome start? I don't know, but I know users on slashdot weren't pearl-clutching prudes, for example.
Sure people "commented on" things they didn't like, on their own websites. Not on platforms from which they wanted to kick others, certainly not as a habitual normal thing a sane person would consider. Yes, "such people always existed", so in that sense it was "thinkable". But it wasn't done as a matter of course, as a way to win debates.
And it's not as unthinkable as you say at all that an individual or organization would attack others for what content they create. Since there has been an internet there's been people who attacked others for their content. I'm not sure what internet you saw 20 years ago but it wasn't the same I saw.