For everyone saying "Customize" this and opt-out/in that. Why not just have Pocket be a pre-installed add-on? That sounds like a compromise that would satisfy both camps and fit in with the Firefox philosophy.
> Directly integrating Pocket into the browser was a choice we made to provide this feature to our users in the best way possible.
I don't know why (or whether) this direct integration makes such a difference compared to providing it as an extension, or even what is 'best' about it (fastest? Easiest? Most consistent?), but that's what they said.