I also work at Google though have nothing to do with Chrome.
This isn't "clear" to me. There are certainly complaints about this change within HN, but there are also people here saying that they appreciate the change, or that they're ambivalent.
But the more important part of things is that HN has what, maybe 10000 active users? Chrome has over a billion. Even if every HN commenter was vehemently against this change, that's less than 1% of 1% of Chrome's user base. If this change makes the browser better (using whatever metric you want, I'd argue the correct one here is privacy), even marginally, for the average user, at the cost of a few people believing that the browser is behaving badly, that seems like an overall good change, doesn't it?
And that seems to be what the Chrome team is arguing, that while some "abnormal" users might see this as an attack on privacy, it isn't, and it's a privacy increase for the uninformed user.
I think I've seen exactly one potentially compelling argument, which is that it may now be easier to accidentally enable syncing when you don't want to, since its a single click instead of entering a password. That might be true, although I'm not 100% certain, since I've logged into the wrong chrome window before, and that would have enabled syncing in a previous world.