Cannot speak for the US, but in Europe immigration is connected to crime increase in general. The Ukraine refugees are one of few statistical exceptions.
I think a lot of people are forgetting or at least choose to ignore that DHH is Danish (and specifically a Danish expat) and is probably more inclined to have controversial views on immigration from majority Islamic countries. That's not to give his statements a pass, but to give them some needed context.
And, indeed, if he'd been talking about Copenhagen I suspect at least some people may have looked the other way.
Saying what he said about London is, at the very least, a fascinating example of failure to stay in his lane. In fact, if one were of the mindset to be denigrating immigrants, one could, perhaps, raise questions around what business a Dane has telling Brits which members of their former colonies do and do not count as British or, indeed, what it means to be British.
I think a lot of people don't know why being Danish is relevant. Is there some reason why controversial views on immigration might be less suprising coming from a Dane?
Denmark is the rare case of a European nation where its center-left listened to feedback from the electorate early on and earnestly adopted policies restricting immigration and refugee admission. As a result they had no populist backlash, and that policy position is uncontroversial to hold publicly.
And no, I'm not saying that Danes are racist.