[PunchyHamster]

> It means "We think we have something that could help performance based on a dubiously applicable idea, but we have no real workload to measure it on. But we're going to do it anyway."

the problem is that it doesn't say that directly so people without experience take it at face value.

[qu4z-2]

The commonly cited source says, when you take the entire sentence, "We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil." and continues "Yet we should not pass up our opportunities in that critical 3%."

There's only so much you can do with people who will not even take the complete original sentence, let alone the context. (That said, "premature optimisation is the root of all evil" is much snappier so I do see why it's ended up being quoted in isolation)