That's where you're wrong. The reason they gave is "we don't want to confuse casual users with comiplcated functionality" or something along those lines, which is absurd because there has always been power user functionality available to those that need it without hurting the casual user experience, and installation of extensions is up to the user, casual users don't need to do it.

So since their explanation doesn't add up, tell me, why do you think Mozilla, who gets most of it's funding from Google, decided to make add-ons such as Privacy Badger and umatrix and cookie autodelete unavailable to us to use?

Never just assume someone does something for a good reason. Never assume malicious intent either, but don't just take it laying down when a tool you use no longer works for you. If a tool keeps getting worse and worse from a user perspective, it is because the changes being made aren't made with the user in mind.