The same website shows a significant amount of traffic over central Europe too.
While there is no significant ash above FL200 over most of Europe (according to
this link) there is still a cloud from SFC-FL200.
So have most European airlines just decided to ignore the warnings while we Brits are happy to wait in ever-lengthening queues for a trip on Grey Funnel Lines from Spain to Portsmouth? Is it a Nu Labor conspiracy in an attempt to prove they can take firm [Naval] action when needed?