Saw two people in my life who pretty much destroyed theirs because they simply couldn't stop playing WoW whatever happened around them in real life.
I had times in the past where I almost went that route and only because I knew that it would happen if I ever started an MMO, I never started one in my whole life even though I was very interested in them.
Online multiplayer in games like Halo was still enough to almost destroy my future.
Thankfully I can handle it now but yeah, gaming can be pretty problematic for many because it sucks you in more than other media