Well, to be fair, MySQL has a storied history of implementing 95% of a feature, calling it good enough, and shipping it.
And while, as a Postgres user, my tone here may be a little snide, I also say this with grudging respect: I think there is a point at which implementing n% of a feature X and calling it X (rather than MaybeX or MostlyX) does give you some momentum and practical compatibility that you wouldn't have otherwise. Is it dishonest to hide the limitations regarding the edge cases in some documentation no one will read? Maybe. But will providing the feature solve more problems than it causes? Quite possibly.
I don't agree with MySQL's decision with respect to UTF-8, but I do understand it.
That's an important piece of context, thank you for pointing it out. Engineering decisions occur in a cultural context of mere humans making decisions, and we do well to remember that.
And while, as a Postgres user, my tone here may be a little snide, I also say this with grudging respect: I think there is a point at which implementing n% of a feature X and calling it X (rather than MaybeX or MostlyX) does give you some momentum and practical compatibility that you wouldn't have otherwise. Is it dishonest to hide the limitations regarding the edge cases in some documentation no one will read? Maybe. But will providing the feature solve more problems than it causes? Quite possibly.
I don't agree with MySQL's decision with respect to UTF-8, but I do understand it.