Same reasons I take issue with the phrase "best practice". Besides my cynical POV that when people start talking about "best practices", they are about to tell you that whatever you're doing is wrong, and here, let me sell you on NEW_DEVELOPMENT_PARADIGM_FAD. I'm all for making things better, but I'd argue, there's no "best" practice, only strongly recommended guidelines and some practices that have fallen by the wayside as we learn to do things better.
Replace Best Practice, with Good Practice and it may be less irksome for you, as it leaves it open for improvement, and is not mutually exclusive with other good practices.
perhaps it's really related to the word "Best" and wouldn't be as bad with "Good" but i've found that these things, more often than not, are neither. "Best Practice" is just a concise reformulation of "this has been blogged about a lot and everybody else seems to be doing it", it's an incantation intended to shutdown brains and differing views. i'm just moving off a job in a company full of "Best Practices" that cost shitloads of effort in exchange for negligible benefits. nobody stopped to weigh the pros against the cons, because they're industry best practices, so they gotta be good; doing what everybody else does gets you more job offers than doing what works well.
