This is how online services meeting the regulatory requirements and creating a positive image of being privacy-respecting, "we are giving people a choice over their data", meanwhile still allowing the unhampered collection of personal data in practice.

Or the principle can be worded as, "If everyone opt-out from the tracking in their privacy settings, our business is finished". You can opt-out, but their business model remains the same, and you are simply an outlier.

As I see it, the most interesting case study is Do-No-Track. When DNT has just became a standard, the response was mostly positive. Then something dramatic happened, Microsoft enabled DNT in IE 10 by default! Then amusingly, it triggered a total backlash from the industry. If you see the principle, it's easy to explain that.

But Microsoft surely understand this point. Then why did it decide to do this? I highly suspect Microsoft's decision was a conspiracy to intentionally kill DNT, even if most people won't active it anyway, but they may believe that having a simple and universal privacy toggle is still being a potential threat to the business of the industry, so they decided to sabotage it by making it default-on, thus nobody will treat it seriously, and Microsoft can use the "we care about your privacy" as an excuse.

One can't fix the privacy issues with a privacy setting. One needs to have an alternative business model in the age of Surveillance Capitalism.