While it's true to say that our obsessions could be more a more productive one, no-one chooses the things that they like, the things that get them off. It's like who you find attractive or love, it's an unavoidable unquestionable desire to spend more time with the person, subject or object that draws you to it. Like a moth to a flame sometimes but so be it.
We ARE living our lives, we wouldn't be able to post if we weren't, well maybe Zombie Chewbacca could still post, but to suggest we're wasting our lives... what should we be doing with them?
I don't think that being a fan of scifi, horror, westerns, French comedies, Godzilla, porn etcetera stops me from going out and meeting people, having fun and being successful in my chosen field (which happens to be film) any more than barrackers for the Roosters and Bulldogs game last weekend were unable to live their lives to the full.
But as many have said before me, all things in moderation.