Because once the data collection starts it only grows, it never gets smaller. They also never just grab a few flags but everything the environment allows them to take and employ "growth hackers" to find more.

When new employees walk in, any moral conviction that existed in the first implementation takes its leave.

Honestly, given the near certainty and repetition of history, your disbelief comes off as naivete.

And when that happens, you can complain. But until then, I think it's widely considered okay to collect small amounts of data (literally a single bit) on which features are enabled, so features can be better worked on. Firefox does it by default for example.

Complaining doesn't help when your data has already been bought and sold by ten different brokers.

And I'm a strong supporter of privacy. Collecting statistics on whether or not you enable a feature is basically universal. Use DDWRT, I do.