The uke is a lot easier to play than a guitar so it is natural to gravitate towards it, most people just don't have the time to mess around with more than one instrument. The beauty of the recent ukulele revolution is that it has made music a lot more accessible to a lot more people because the uke is relatively easy yo get a start on, and they can be made for a low purchase price.
A challenge once you have mastered a lot of chords and can strum and sing along with ease, is to move on musically. You can do this playing a uke by learning more about music, moving up the fretboard and so on. And the greats like Herb Ohta have demonstrated, you can spend your whole life mastering the uke. So you can easily justify leaving your guitar behind.
One thing to avoid though, is to avoid facing the reality that other instruments are harder to play and that they can do more or different things musically than a ukulele. In a band or an orchestra the tune is created by all the instruments, even a triangle, each with its own part, and if you only know ukulele players, maybe you would get a lot of benefit from joining some other musicians instead of being xenophobic about your uke playing. The hard part of joining the other musicians is doing the work required to develop the same skill level/respect that they have when playing your ukulele, but it is probably worth it.