I sympathize with your position, especially regarding Taiwan, but I wonder if your early rejection was as effective as employees rebelling? One need not take the most effective route, but given the size of Google, when I was in a similar position to yours I justified it by saying if I got an offer, I'd make it very clear I'd want nothing to do with the censorship work for the exact reason you listed.
Both are good. I'm sure Google carefully tracks why candidates decline jobs at Google, and if enough of them say "I can't work with you because you're doing specific evil thing X," then it becomes more and more worth it not to do X.
Similarly, if internal morale is in decline and reports come back saying that it's because of X, that also has a real (and quite possibly quantifiable) cost.
Do you think that recruiters spend time forwarding your response to someone at Google who actually cares? I usually decline jobs/projects outright, but I wonder if I shouldn't waste some time on interviews before telling the company why I won't work for them. It's not like there's a shortage of projects, and I'd like to maximize my political "leverage".
