Including that language might improve performance on certain tasks, even if “reasoning” isn’t something LLMs are capable of. Heck, they’ve even been shown to sometimes perform better when you tell them to “Take a deep breath”: https://arstechnica.com/information-technology/2023/09/telli...
As the old saying goes, “If it’s stupid and it works, it’s not stupid”
That saying must have existed before computer science though. These systems will forever be changed in ways purposely away from nonsense working positively.
The same reason people still think you have to do certain things with batteries which were only accurate for a certain chemistry 50 years ago, we are actively creating "old wives tales"
As the old saying goes, “If it’s stupid and it works, it’s not stupid”