It's not really good reason since they don't endorse specific country when they accept certain fiat. And it's rather ironic when Wikipedia promote similar ideology (free and open knowledge).
I didn't say it's the best reason, I said I can't argue. It's the same as they would have said "because we no longer want that".

And for the rest... there used to be a saying: "do what the priest says, not what de does".

I would say that that was their stated goal, but it has been captured and is now peddling a highly skewed, non-independent, biased and non-objective form of "open knowledge."
This is easily a feature of centralization and a result of getting far too popular.