It lacks action compared to Call of Duty, BF3 and other shooters because Half-Life is a story driven game. The combat is shooting sure, but it's story driven. Gordon Freeman is one of the most beloved game characters ever because of the story and atmosphere/way the game plays out.
You have to play it like a story game that has shooting, and not like a shooting game that has a story, if that makes sense.
I get what you mean. The story just didn't hold my interest. I'm not generally a huge sci-fi fan so that may be why. I loved Fallout NV because of the story though, played that game way too much.
Right now i'm actually playing NOLF on PC, still a badass game to this day.