Personally I think money spent on most AAA games isn't worth it. The money makes them look better, but as far as mechanics go they are at best comparable to other games, and more often - reduced in scope and complexity, because the development focus was elsewhere. Look at Might&Magic: Heroes VI. 3D graphics, 5 or 6 factions down from 8(9), no user-friendly map editor. Instead of text story pop-ups of the past, you get cutscenes (in a strategy game!!!). 3D graphics is awfully expensive to make, complex, and limiting compared to 2D. I would prefer the money to be spent on AI, interface and pathfinding algorithm research. Or funding new different types of games (Kickstarter is still snowballing :-)
You may as well ask if blockbuster movies are worth the investment. The answer - depends on your point of view. But don't be fooled - you can't just take a movie budget and assign it elsewhere. People do what they enjoy. They also fund what they like. The directors, actors, cameramen probably wouldn't want to work as teachers or in healthcare. The investors, for whatever selfish reasons, don't see funding these things as a good idea.