This “feature” is abused terribly around the web. For every site with useful notifications like gmail, there are 10 which misuse it. Yesterday I had the misfortune of misclicking on the prompt from a website. I started getting notifications like “YOUR COMPUTER IS INFECTED WITH A VIRUS”. Turning off notifications for that website took at least 4 clicks through Chrome settings. Good to know there is a setting to turn it off completely on Firefox. If I personally actually wanted notifications from a service, I’d install the mobile app.

Second, Mozilla seems to use telemetry data responsibly and well. Turning off notification prompts by default can’t possibly be done unless you have the data on acceptance rate on different types of prompts. If you’re making such decisions based on your intuition you’d likely get it wrong.

I ask the folks on HN who constantly criticise the collection of such telemetry, what did I lose as a user when Firefox collected this anonymised data? More importantly, how would you have made a decision here without the data? Intuition? (I’d request that no one reply with platitudes like “with enough data nothing is anonymous” and “you’re making a nothing-to-hide argument”)

You're making an assumption that their decision was based on data they collected. Not worth discussing data privacy with you over that-- they may have very well done simple user testing or done it on a whim of a few users that put a good case forward.

He's also failing to acknowledge that using telemetry in a constructive way does not preclude using that telemetry in a malicious way as well.

You can get started here - https://github.com/Microsoft/vscode-extension-telemetry and https://github.com/Microsoft/vscode