While it might not matter to you, a lot of people do consider the continuation of the UK as a whole important and of historic significance.

It used to be important but Thatcher and Major (continued under other government) ideologically set about destroying the post-war consensus which help to make modern Britain and bind its people togethe , Just alone think of all the things that used to be owned in common that had "British" in their name that have been sold off to the City or to other countries. The British identity has been breaking down for decades and add the general divergence in political thinking between Scotland and England and it's clear that the union is on life-support - many can't see the point in it continuing.

Yes, family and friendship ties will always exist and be paramount and the current constituent nations will always be friends and allies, but the UK can't rely on shared History and sentiment to keep it together if the relationship is not working that well in a supposed union of equals.