Firefox can't even be Firefox on iOS and is only a reskinned Safari. So, I'm more concerned that Firefox for iOS even exists since it's kind of a bait&switch to what a Firefox user would expect the browser to be. How would we all fell if we downloaded a browser like Firefox or Chrome on the desktop but to find out it was really a totally different browser?
So playing by the reskinned rules, blockers are not allowed in the way someone using Firefox would expect. Not just blockers, but any extension. It's such a totally not-Firefox experience, that it is even hard to type that it is Firefox.