> It's not actually ethnicity he's talking about, it's skin color. Ethnicity is cultural.

DHH says people are not "native Brits". The literal meaning of that is ethnicity, not skin colour. Of course DHH might be using this as code for white, but it is not the literal meaning, and (as another comment points out) the statistic he quotes is for the total of the ethnic groups that are considered white British - it excludes white people who are not ethnically British.

If he is, then he is, again, projecting his own views onto a culture he does not really understand. Some people from European countries (e.g. an Albanian illegal immigrant) are far more likely to face hostility than some non-white people (e.g. a professional affluent South Asian with a British accent). Someone recently commented that a racist who they know well would not mind my (brown) family because we "sound posh" so would prefer us to people like Poles.

> How many generations is enough to become "native"?

Define native! Are white Americans native in the US, and are Afrikaners native to South Africa, etc.? It is an ambiguous word.

The problem disappears if you drop the adjective native and just say "British".

> Why exactly aren't people of any skin color who live in the UK, speak English, and believe in the full package of "Western values" (equality, freedom of speech, religion, rule of law etc) and "English behaviors" (queueing, tea, whatever)

I think the problem with that definition is that lots of people how have never even lived in the UK believe in those values and drink tea and even queue. I know plenty. Also, English or British? British is a nationality, English is arguable an ethnicity (as are Scottish and Welsh).

> It's extremely worrisome.

I agree there, and it is very disappointing to see DHH spouting this.

> Define native!

That's why I put "native" in scare quotes.

> I think the problem with that definition is that lots of people how have never even lived in the UK

That's why I wrote "live in the UK" first.