It's just that not playing those games when they are new, but later playing games that make use of those innovations, don't in any way constitute 'missing' something. Yes, a game can be important... heck it can be really important without being all that good of a game.

Part of what made HL so interesting to play was the newness of what it was doing. For some, it was a large part of the enjoyment of the game... making it somewhat artificial and not something that can be replicated once those innovations filter out into other games.