From what I've read, the main objection to this isn't the linking of the accounts for people who want it, it's that there's no way to opt out for people who want to use Google services on the web but don't want to log into the browser itself at all. I don't think there's any reason that they couldn't make it so that logging into Chrome automatically logs you into your Google account on the web as well without doing the reverse as well. To me, this feels like an even worse version of the "opt-in by default" issue; to opt out, you also have to opt out of logging into any Google accounts at all while in Chrome, which is a huge ask even for privacy-minded people who don't want to log into the browser itself.