I've always been surprised by this metric. True, if the game is only a couple of hours it can be a bad investment. However, I can think of at least half a dozen ten hour games that have left me with a more memorable impression than some games I've played for ten times as long.
To my teenage self it would make sense, though. Enough time but not enough money, which makes long (sometimes artificially long) games a necessity.
Personally, I see it as an equation of Story/atmosphere quality x mechanical pleasure x length where story is the trump card.
A game like SOMA has low mechanical pleasure (it's a walking simulator, essentially) and a short length, but the story and atmosphere are so high that I will forever remember the experience.
Cyberpunk has decent length, decent story/atmosphere (obviously this is subjective) and decent mechanical pleasure so it's a great game.
CoD has a short length, decent to high mechanical pleasure (well at least I hope so for their sake since it's supposed to be about the multiplayer shooter replayability) and low story/atmosphere because it's just a string of action movie clichés. I think that's what makes it sound very mediocre compared to Cyberpunk.
Other gamers might see mechanical pleasure as the trump card, and I can definitely understand their POV (Portal 1 for instance). I'd venture a guess that length is rarely a trump card except if you are stuck with the games you do have. Usually for length to be the most important factor, you need at least a decent degree of the two other factors to go with it. For example, what people love about Skyrim is that the basic gameplay of walking around and doing things is fun and you can just pick up the game everyday for months and still have things to do. The story is nothing special, but the atmosphere is comfy enough. You know the game is there for you when you come back from work.
Amount of time is a really bad measure of what you are getting. Quality > quantity. Not saying CoD is an example of quality (no idea) but we already have enough padding and needlessly repetetive tasks in many games.
To my teenage self it would make sense, though. Enough time but not enough money, which makes long (sometimes artificially long) games a necessity.