Because I enjoy variety. While I certainly have my preferences, just watching certain genres is too restrictive for me. And I actually find it very fulfilling when a series I had little expectations for manages to surprise me. As to why for this series in particular, while certainly not an “A” list title, I do have an interest in myth/legend/folklore/fairytale themes. Considering it’s getting a 3rd season, apparently I’m not alone in finding it at least somewhat enjoyable (though I do hope they decide to wrap things up this time around, as I could see losing interest if things drag out too long).
I generally prefer romcoms over romantic drama’s, but the Fruits Basket remake proved that there are exceptions.