By virtue of the fact that hiding blockchain properties is not the same thing as making monetary tokens "indistinguishable", no matter how much Monero shills try to conflate these two concepts.
monetary tokens can only be indistinguishable, if, well, we cannot distinguish one from another. Now, monetary tokens that have a traceable history to them, will of course be distinguishable from tokens that have a different history to them. Napoleon's handkerchief is different from another handkerchief, because once it belonged to Napoleon. That sheer fact distinguishes this particular handkerchief from all other, similar, handkerchiefs.