There are many reasons that people have for wanting to play the violin. Here are some of the reasons we hear most often:
Regardless of where the initial inspiration for playing the violin comes from, if you drill down far enough, we also find that with almost any learner you'll uncover a desire to be able to communicate emotionally with other people through music (and by extension, through the violin).
Whatever the fundamental desire is that makes you want to play the violin, it's worth being aware of it. That way, when you hit difficult challenges in your practice (it will always happen!), you can keep motivated by staying focused on the big picture and on your long-term goals.