Great Britain lies on the European continental shelf, part of the Eurasian Plate. The United Kingdom is also culturally and politically affiliated with other European countries. Why is it not in Europe?
They are referring to Europe as a political entity not as the geographical feature. GB has generally considered itself separate from 'Europe' as a polity.
It would be like referring to someone from Cuba as 'American' because they are from North America. Technically true but people assume American means someone from the states.
In the UK, and particularly England which is a lot more euro-sceptic than the rest of the UK, it's a standing joke that the UK or England isn't part of Europe, and "Europe" is often used to refer to Europe or the EU excluding the UK.
Great Britain lies on the European continental shelf, part of the Eurasian Plate. The United Kingdom is also culturally and politically affiliated with other European countries. Why is it not in Europe?