For the most part, I would say that it "does not incentivize" sybil attacks. I think "disincentivizes" overstates it.

Although, one way that it actually may slightly disincentivize sybil attacks is that other users can vote between two sybil accounts, say sybil-1 and sybil-2, which would reduce the curation rewards of (sybil-1 + sybil-2) as compared to a single account voting the full weight all at once.