Why is there a bias against MP only games?

[outlawauron]

fatslob-:O said:

pokoko said:
It's kind of funny, really.

10 hour single player game -- "I can play it again if I want! Yay! I might play it three times and get 30 hours total! 30 hours makes it completely worth the money!"

Multiplayer game you can put hundreds of hours into -- "Sure, I played this game for 50 hours but what if it gets shut down a year from now? 50 hours of gameplay is a waste of money!"

Except hardly anyone pours that much time into a game, let alone complete them ... 

Shallow example ...

But the average user of these games do pour a ton of time into them...