Literally 99.99% of Firefox users did not use the built in RSS support[1].

I love RSS! I also never used the built in Firefox RSS support because it was not very good. Mozilla also compiled a helpful list of alternative RSS readers for the 0.01% of users that used this feature and made it easy to export your feed list[2].

[1] https://www.gijsk.com/blog/2018/10/firefox-removes-core-prod...

[2] https://support.mozilla.org/en-US/kb/feed-reader-replacement...

Market research, in this particular case adoption rate, also indicates that people love giving all their privacy away to google.

Good point. But Pocket isn't harmful, especially if you don't use it. In the worst case, it makes the Firefox installer a few kb larger, that's about it.

The same could be said of the RSS support.

True. The big difference is that users use Pocket but didn't use RSS.

A lot of people have a really strong negative perception of pocket. That should be enough to be able to remove it.

Meaning the nontechnical set of users that don't go out of their way to disable telemetry, at least...

If you disable telemetry, Mozilla won't know about you. If you want Mozilla to cater for you, don't disable telemetry?

Telemetry should never be enabled by default without consent. Its a dark pattern.

It leaks information about my browsing history.

These "missteps" are the reason I don't use Firefox. With Chrome, I know Google are watching. But I also know only Google are watching. They're not bundling irremovable third party apps in with the browser, or installing extensions without my consent, or sending my entire browsing history to another third party.

Mozilla have done all these things, and when called out on it, they don't seem to realise they've done anything wrong. That crosses the line from naive to actively malicious.

They definitely have a few bad apples in management.

Market research show that noone used RSS/legacy addons/all the other customization options, yet Firefox market share somehow plummeted after they removed all of it.

Literally everything I liked about Firefox is gone, so I have no reason not to use Chrome instead anymore. They are mostly the same, Firefox is just uglier than Chrome now and I can't change that anymore.

Neither does RSS. Forgive me if I'm wrong, but isn't Pocket developed outside of the main Mozilla tree?

I don't remember the current status. It's probably developed outside of the main Mozilla tree, as a number of other features.

But the big difference is that people actually use it.