Are bitcoins ethical?

"...currency whose value is determined by cryptographic algorithms"

Not at all. The value is determined by the people who are using/trading bitcoin in addition to its scarcity. Which leads to...

"Anyone can create a Bitcoin..."

Anyone can mine a bitcoin, but its supply is capped. Perhaps this is just a bad use of the word create but I feel it's necessary to clarify that they can't be infinitely created since this is such a common misunderstanding. For now, until the cap of bitcoins is reached, they can only be mined by anyone.

I think the writer presumes that BitCoin can't be audited. Which, I think, is a very false presumption. It isn't currently, and it should be. The best outcome for BitCoin is that it becomes second legal tender (with all the auditing and rules that go with it). This will increase competition with other currencies (and their systems) which is a good thing, IMO.

Why not?