Ok, in my mind it went like this:

You are a game dev and want to sell my game on steam, steam allows only games with at least 4 achievements to be eligible for distribution on their platform, you think of 4 achievement that more or less make sense for your game, you ship the game with the achievements.

You wouldn't have put the achievement there in your creative vision, but you did because Steam forced you to. The code is still under your control, but not really because contract.

Yes this is hypothetical, it's already being established this is NOT how steam operates, unlike other publishing platforms. Considering MOST games ship on multiple platforms, it make sense to put achievement in there to please xbox and leave them in for steam.