You're either musically inclined or you're not. If you are, you'll go through spells where maybe the guitar isn't your best friend, but you'll always be thinking about music, riffs, passages, timings and the like. If you're not - well, ya, interests are like seasons man, they come and they go. Inspiration is the key for me to keep at it - and unfortunately, time is my only deficit. I'd love to have 3 to 4 hours a day to play - I really would, I'd cover a lot of territory and it's something I'm trying to make happen. But you know, you may just be at a point right now where you're lacking inspiration - doesn't mean you fail to be a guitarist. Or a musician. Or a musically inclined person. Hell, puttin' her down for a while may be exactly what you need to get fresh with it again.
I ended up buying this ridiculously in-depth and expansive soft synth a while back. Learning it, mapping it, integrating it with my other plug-ins and software has been a complex, complicated and time consuming process - but it needs to get done. However, it's eating into my guitar time. Interestingly enough though, just by working with it loosely, I'm already scratching riffs and thoughts and phrases and the like down in my music book as I come across awesome sounds, beats and textures. It's becoming its own fountain of inspiration.
Gettin' some play is also a good way to revive the musical spirit... A little action, ya know? Go get 'em tiger!