Erik is a little trollish when expressing his opinions. From what I noticed, he loves flames. People either love his style or hate it. I guess you're in the later group - personally I don't mind when he's mocking something I care about, because from what I observed, he's always joking or half-joking and he'll say the opposite of what he just said in a couple of weeks.

> He is dismissive of "reactive programming" as nonsense from architecture astronauts, without giving a remotely fair description of what it actually is.

That's because his presentation is from React 2014, so he can fairly assume that the audience has some idea of what he's talking about, because "reactive" is the freaking topic of this audience - http://reactconf.com/

> if you're throwing punches you should know what you're talking about

Well, he kind of does. He's one of the architects of Reactive Extensions (Rx) and now he's contributing to RxJava. I don't agree with many of his opinions, for example I think they made design mistakes while architecting Rx, but he's OK in the knowledge department ;-)

> At 17:30 he makes a joke about a Steve Jobs function that says "iPhone", "iPad", "iCloud", and then "terminates naturally". Holy bad taste.

He also makes the same joke about himself - was trying to explain how streams are terminated, either naturally or by error (the joke on himself was that he was fired, i.e. onError).