Some of it is inflammatory and though I don't agree with such treatment I can see why he received it.
One example is this: "Node.js has linear speedup over multiple cores for web servers."
In general it is possible to say crazy and inflammatory things without repercussions only if these 2 things are true: 1) There is already enough dev karma and respect 2) The things you say are true.
Think of Linus. Linus rails on people publicly and is quite insulting. But he has both lots of dev karma and also most stuff he says is true.
Think of average Joe programmer some place on a mailing list. They don't have public dev karma and even if they are right and say true things, if they say it in an insulting way they will face repercussions. Others might point out that he is right but he will still have to handle negative responses coming his way.
Ryan in this case has lots of dev karma (#1) but he messed up (#2), he said things that are wrong and because he put them in a rather insulting tone, this amplified the response.