Your question reads as though you think Davlight Saving is a European idea that the UK simply follows. In fact, the UK was about the first country in the world to adopt Daylight Saving in 1916 - though Benjamin Franklin, the American statesman had suggested the idea in the 18th century. It should also be remembered that UK clocks are always one hour behind the rest of the European Union; some people think that we should come into line, by advancing our clocks by one hour.
All the countries of eurrope do pretty much the same thing. And no, we shouldnt change our clocks, france and spain chould change theirs. We set the global zero for time at Greenwich. Having the global zero moved by an hour would be silly. France and spain should move to our time by their physical position but france has always refused to because they want the world to recognise the Paris meridian not the Greenwich one.