Hmm, that's an interesting question. To be perfectly honest, I don't have a definitive answer. I would like to think I ship for fun. After all, it's nice to pair up characters and role play different scenarios in one's head. Umm, I guess if I force myself to answer based on psychological reason, then the motivation behind my shipping tendences could lie in my own feelings towards love. Basically, I do believe in love, but I just don't think it is for me. Not that I haven't found it, it's just that I don't need it. I'm at one with myself and yet, I am so fascinated by the idea of love and the many different forms of it. I think for that reason, I don't have any specific kind of shipping that I favour more than others. My ships range from the romanticized Disney kind to the dark and twisted kind.
Being a writer, I have the freedom to come up with whatever. In fact, I probably ship my imaginary characters even more than any other "real" pairing because they are, in a sense, very real to me (not in the schizo way, mind). After all, I created them and it makes sense for me to be invested in their lives, which includes all romantic entanglements. Fantasy can be a great way to live out desires, even if they are not your own. However, as much as I like fantasy, I have just as much love for realism. I don't like it when characters act completely off-script from the sake of pairing them up.