I've never been happy with search engine integration with any browser, but that's been a dead horse for well over a decade now. Besides, I can remove those services from Firefox and substitute any search engine I want, or none at all. I can't change Firefox's choice of "read later" providers because it's hard coded to Pocket. They chose for me, and don't allow me to alter that choice. With search engines at least I can control the service provider.
If they provide an extension, you can use whatever read-later provider you want. You can trivially remove or disable the Pocket button. I agree Firefox made a mistake not integrating this as an extension, and whether it should be included by default is a valid question. But you're really exaggerating any amount of "evil" being done here.
Well I never actually said it was "evil", just outside the bounds of what I find acceptable. And it's interesting to see that, after all of that back-and-forth, in the end you and I agree: It should have been implemented as an extension, not hardcoded to one specific provider.