Well it's also a matter of taste (and luckily I can't change that).
And here is my way to make it more KDE3-like:
1. Set Desktop to Folder View (as in KDE3)
Right-click desktop > Folder View Activity Settings > Activity > Type: Folder View. > OK
2. Remove Desktop Folder
Right-click desktop > Unlock Widgets > select X marker when cursor is over Desktop Folder
3. Switch to Classic Menu Style
Right-click Menu icon > Unlock Widgets (if applicable) > Switch to Classic Menu Style
4. Lock Widgets
Right-click desktop > Lock Widgets
[3 is also a less computer resource demanding than 4.
Try System Settings > Look & Feel > Desktop > Desktop Effects > remove mark at Enable desktop effects > Apply
This is my very short manual.
You can adjust KDE4 more and easier to the individual wishes then KDE3.
And that's the reason it has more settings and is thus a little more complicated.
(and it need ~ 100MB more RAM to achieve this)