I agree with the other answers that this pattern is poor and violates various software engineering principals. Apparently your coworkers don't care much about them. What you need are example use cases where this pattern fails or is awkward to use. Here's a couple:

1. The game is Bridge. After bidding, sometimes you must change the name of one of the four existing suits to "trump". Try writing that code. I predict it will be icky, buggy, and may even break the existing code.
2. The game is Hearts. Rename the Queen of Hearts to "The Lady". (PG version).
3. Your game is a huge hit in China and Armenia. Add a menu for language that they can pick anytime during tha game. You must get this version to market before your competitors do!

I agree with the other answers that this pattern is poor and violates various software engineering principals. Apparently your coworkers don't care much about them. What you need are example use cases where this pattern fails or is awkward to use. Here's a couple:

1. The game is Bridge. After bidding, sometimes you must change the name of one of the four existing suits to "trump". Try writing that code. I predict it will be icky, buggy, and may even break the existing code.
2. The game is Hearts. Rename the Queen of Hearts to "The Lady". (PG version).
3. Your game is a huge hit in China and Armenia. Add a menu for language that they can pick anytime during tha game. You must get this version to market before your competitors do! Oh yeah, its a multiplayer game and the big Armenia vs. Shanghai match is coming up, with a cable TV audience in the USA.