Best practices stem from the practical, not from the theoretical. 

A theory explains reality. The current theory explains reality best. A theory is valid as long as there is no theory explaining reality better.

Best practices are ways of doing things. The practice is based on year long experience in the real world. Grandmother told us how she did it. It is not theory. It is not proven formally, by mathematics. It is proven by action and results.

Best practices are perennial. They change very infrequently. Theories change frequently.

In IT best practices are independent of technologies. Examples are: separation of concerns, layering, encapsulation, decoupling. 

Best practices exist for a reason: they work.

A theory may explain why they work. But it is not necessary.

Best practices have been around for years. They were not invented half a year ago. They may be theories. More often then not theories about the applicability of technologies.

I think we need to question “new best practices” .

Instead we must rely on grandmother’s wisdom. 

*All of this very likely inspired by (or rather, stolen from Nassim Taleb’s Anti-fragile writings, and the Lindy effect)