[having come to a similar conclusion earlier, he extrapolates:]

I do not think that any of us did, with the exception of Touko, perhaps. Even she was upset about having to dirty her hands so literally. [which he says cavalierly because surprise he doesn't care about like 99% of the things he pretended to care about while he was alive...]

I believe the criteria was simply people who would do what was needed to reach or avoid the provided incentives.