The reason Cathay wants you to do this survey is nothing to do with picking out individuals and crucifying them later or alternatively, that they've done a 180 degree turn from all past behavior and suddenly care what you think.
If you have a look at what is going on in the data analysis field the big rage now is all about metadata and what you an derive from that. ie Think Snowden and the now not so secret NSA program. The unique password is not about your individual identity. It is about which group you are in. It tells them whether you are based, HK on expat conditions, HK on local conditions etc. they can then derive what each group cares about in relation to the other groups and apply the findings to their well worn divide and conquer strategy. That is why you should not do this survey. As others have said, there is no coincidence this is all happening halfway through these conveniently long negotiations.