dont quote me, but my guess would be because of how closely related the instruments are.
take a guitar. normally tuned EADGBE. now take a bass. normally tuned EADG... the last four courses of a guitar. now take a baritone ukulele. DGBE. basically the first four courses of a guitar. now take a tenor through soprano ukule tuned GCEA. basically the first four courses of a guitar, capo'd on the 5th fret. and then we can go into all the "alternate" tunings.
im not saying that having a place to talk about drums wouldnt be nice. but in keeping with the theme of this forum, i cant see how it would fit in, other than the drum's obvious importance in any musical setting. having a percussion section would diversify this forum, but not benefit it like an actual forum dedicated to percussions.
