man

KDE comes with numerous commands which are entirely undocumented, including command-line-only ones. Typically these would be executed by other programs, but not always, and not always successfully. Plus when you are looking for a command without remembering exactly what it's called, and tab-completion gives you loads of options for undocumented binaries in your $PATH, it's really annoying. Having at least a description of what the program is for and what its options are would be rather more pleasant than using 'strings' on the binary.

I realise this argument is somewhat weakened by the fact that I cannot remember off-hand what commands I've had these problems with, but they are a contributing factor to KDE4 annoyance.

On a related note, are the GUI parts of KDE4 mostly documented these days? Last time I tried with the KDE4 docs they were a combination of missing, outdated, and useless (that's not just a KDE4 thing though: loads of apps in KDE3.x for years kept documentation for versions long since gone). I know for certain that there are parts of KDE4 where there are confusing options with absolutely no description of what they do (try getting some documentation on the desktop effects settings in systemsettings).