The pool sybil is due to pool mining, not ASICs. Even before ASICs, there were pools nearing 50% hash rate, outcries, and pools subsequently "shrinking" (though that may have been a sham).
Actually, I say the reverse is true: ASICs represent one CPU, but have disproportionate voting power, that is the essence of sybil.
No the essence of sybil is that you can make one appear to be many (and get more votes or whatever benefit it is from appearing to be many). You can't do that with ASICs. One is just one.
Everyone is using ASICs now so there isn't really anything disproportionate about it.