There are many reasons to play the guitar.  It is portable, fairly easy to get started with and is very versatile.  Getting a decent sound from the six-string can be done quickly after learning how to hold the strings down and pick properly.  There is no checking your emboucure in the mouthpiece, wetting your reed or memorizing invisible positions.  There is also quite a repitorie available in almost every musical style.  It is a wonderful solo instrument but really shines as accompanying other instruments.  But mostly, the guitar just sounds so cool!

What sounds better than a guitar?  Two guitars, of course!  Guitar duets can sound much fuller than duets with other instuments.  There are a good deal of flute guitar duets, violin guitar duets and vocal songs with guitar accompaniment available.  There is some good music in that area but guitar duets can be very rich sounding.  The guitarists can play something as simple as a song from a lead sheet with chord changes or something challenging from classical guitar duet sheet music available to anything in between.

Guitarists playing together can take turns playing the melody and accompaniment parts.  It forces them to listen, blend and keep time.  This is something that other instrumentalists get all the time and take for granted as they play in concert bands and orchestras.  Ensemble playing is great experience but small ensemble playing can be even better.   Developing this musicality and maturity can make the guitarist into a valuable accompanist.  That means that other people want you to play with them.  That is a good thing.

There are advantages of playing jobs as a guitar duet.  The guitarist does not have to have four hours of solo pieces worked up and is not responsible for the whole show.  The duo can trade off and take turns backing each other up.  The synergies of two musicians add to the overall performance, giving a feel of a larger band.  Of course you can play smaller rooms and not have to charge as much as a band.  That can get you more gigs.  Besides, it is fun!