Copping out of an obligation?
Dude, not finishing the story and leaving us all on a cliffhanger for seventeen fucking years and then giving this as an excuse is the real cop out.
Looking back, I actually don't like what Half-Life did to the genre. It didn't push it forward; it made everything after a linear, set-piece experience with minimal replay value. It might have been different back in the day, but it wasn't something I had hoped other developers clung to like they did.