There is a difference between being controversial and being partisan. The talk directly calls out Republicans. Based on what Chris Anderson said, they would welcome a talk on that controversial subject, but it couldn't call out political parties.
We don't want to "call out political parties", so we will ignore the truth that one of the political parties has deviated so far off course, in its anti-science, anti-intellectual, anti-equality pursuit.
But let us not speak of it.
Yes, tribalism can induce such ills as well as invoke cognitive dissonance, but it is not a default setting.
There's a big difference between saying Republicans are anti-intellectual and saying anti-intellectualism is bad for the following reasons. TED is all for the latter and completely against the former.
And there are other parties.