And why would that be, Nigel? Because they have a few grand per person spare to just idly pay traffickers with dangerous dinghies? Feel like delving a little deeper?

No need to dig deeper, although several possible reasons suggest themselves:
Relatives already in UK
Expectation of better treatment here than in France
Already understand and speak English

None of that however goes against my point that in crossing from France to England they are not "fleeing the danger of violence or death".