Yes this is ironic.

But let's not judge the article and assertion based on our preconceived bias against Goldman Sachs. I think that their conclusion “We would argue that bitcoin, and other digital currencies, lie somewhere on the boundary between currency, commodity and financial asset” makes a lot of sense.

Really, Bitcoin does have more similarities to a commodity than a currency (especially a fiat currency). It's fungible, untraceable, and unregulated.