That's hardly the reason, though there are games out there that are not worth the 50 dollars, the majority of them are.
Regardless of the quality of the game, the people still need to be paid, if you're not willing to pay their salary, then don't buy the game. But games need to be made, and for a game to be made, people need money to make them. If that is too much for you, stop playing games, it's as simple as that.
Be happy that they've dropped from the 69.99 price tag that cartridges used to carry. If you don't understand economics and the way the world works, dont complain, but you don't get paid for the same thing, it's part of your being a bickering consumer. Until you have to rely on those prices to pay for your job and feed your family, you won't know.
It's not a matter of "worth" it's a matter of expenses. Without recoupment for production, companies fail because they make no profit, with no profit, you cannot run a business at expense. Those are the facts.