Part of the great Linux experience is the ability to have competing projects with differing philosophies. Part of infinite configuration choices includes the choice of installing GNOME instead of KDE (or one of the dozens of other DEs and WMs).
Personally I much prefer the GNOME design ethos over KDE; I am not one of life’s desktop tweakers, and my Linux experience would be much diminished if that’s all there was. But I’m glad KDE exists for those users who like that sort of thing.