Sure, Yoshiki is a god when it comes to writing songs.
Taiji is also a very good composer, I first thought that Phantom Of Guilt was Yoshikis song and I was very surprised to find out it was Taijis. Also, Voiceless Screaming is IMO one of the best songs EVER, by ANYONE. It just seems that he can't really write lyrics, and he doesn't write too often, or Yoshiki didn't accept his songs...
hides songs don't seem to have as much into them as for an example Yoshikis. They are awesome, some ass kicking rock and great melodies, but they don't have such a deep meaning as Yoshikis and they aren't so epic. Might be that hide doesn't take music so seriously as Yoshiki, but likes music to be fun.