I suspect that more of a press obsession with pretty graphs and dramatic pronouncements than actual public interest. Give the press something more interesting to talk about and it'll pretty soon leave the front page.
The British public think a good trade deal with the EU is more important than cutting immigration when negotiating Brexit [0].
Remember that about 20% of the leavers are 'liberal leavers' - they are pro-migration. Once you add this group to the remainers it's clear that a minority of anti-immigration voters shouldn't decide politics for everybody else.
> Overall, the Swedish press was the most positive towards refugees and migrants, while coverage in the United Kingdom was the most negative, and the most polarised. Amongst those countries surveyed, Britain’s right-wing media was uniquely aggressively in its campaigns against refugees and migrants
[...]
> The discussion of refugees and migrants as a cultural threat or a threat to community cohesion was most prevalent in the British press (10.8%), followed by Swedish (8.2%), Italian (8.1%), Spanish (7.4%) and German (5.3%) newspapers. Another noticeable finding was the high incidence of threats to welfare/health systems in the UK press (18.3%) which was much higher than the other countries in the sample (Sweden 11.4%, 7.9% Germany, 7.3% Italy, 6.7% Spain). The prevalence of negative refugee frames could also be seen in the greater tendency for the British press to link refugees and migrants to crime (8.2%) than in other countries (Italy 4.3%, Germany 3.7%, Italy 2.6%, Spain 1.7%)
[...]
> In contrast, coverage in the United Kingdom was the most negative. Despite the presence of newspapers such as the Guardian and Daily Mirror, both of which were sympathetic to refugees, the right-wing press in the United Kingdom expressed a hostility towards refugees and migrants which was unique. Whilst newspapers in all countries featured anti-refugee and anti-migrant perspectives, what distinguished the right of centre press in the UK was the degree to which that section of the press campaigned aggressively against refugees and migrants. This could be seen in the preponderance of negative frames and the editorialising in favour of Fortress Europe approaches.
