The tutorials take little storage or bandwidth. With several major distributions continuing both kde3 and kde4 in current and planned future releases, it makes logical sense to retain the kde3 tutorials.
Regardless of the past battles between kde3 and kde4, Linux remains a paradigm founded on user choice. Deleting the kde3 tutorials, given the small storage and bandwidth requirements serves no purpose other than to destroy valuable learning tools for the desktop community at large. Both desktops have there place and I for one would like to see this information continue to be available for those that find themselves working on a kde3 desktop - through their choice, or that of their employer or government.