The inductive logic of folksonomies is not "from a standstill is this item good?"

It's "given that others liked this, do you think it's good enough?"

The "given that others liked this" is the compounding loop, a collective intelligence feedback loop.

It allows people with little effort to go "... yeah, sure." Which is less effort than considering it from a standstill.

But that's why folksonomies don't pick the best, they just find a thing that everyone can agree is good enough.

This is true for any Swarm Sifting Sort.