Why make a game like Portal 2?

So after having finished Portal 2 yet again (this time for my Youtube account), I asked myself a question: why did Valve put so much effort into making Portal 2 what it is?

Apart from the obvious answer (which is "to make money"), the amount of work Valve put into this masterpiece is nothing short of mind-boggling. There is an eccentric amount of detail in almost every scene, most of which goes completely unnoticed by the player. The narrative devices in play during the story are strangely complex for the medium. There is honest, deep effort put into this game to make it what it is. The only question is: how is it that a game with this much effort put into it is not perfect, while the original Portal is placed in many peoples' hearts as "the perfect game"?

The answer to this question is multifaceted, but what it comes down to is this: Portal was simple in it's nature. It didn't overstep its bounds or try to become something grander than what it was. It was simple and we loved it for it. Does this mean Portal 2 is bad for trying to be bigger and better? No...but it does lose some of that charm. What it gains for losing that charm is arguably for the better however. Portal was a game that was perfect...but Portal 2 is a game that can make you laugh, cry and feel scared. Portal was simple fun, Portal 2 was an experience.