At 50x designed max load bad queries would be one of the easier problems to solve. We design systems all the time that have hard scaling limits, and it's only a problem when you operate the system past those limits. e.g. I wrote a service with ACID assumptions from the underlying database but now the largest ACID db box I can buy isn't big enough. Oops. There's a bunch of possible ways around that but they usually involve a nontrivial amount of engineering effort.

I wouldn't expect any service to survive that much unplanned load. Maybe they could've estimated better, but how likely was it for the game to go viral? Worth sinking lots of dev time into and delaying launch? That's a hard question to answer without the benefit of hindsight.