Don't know why you are getting downvoted when you are completely correct.
There's so much that Mozilla could do structurally, but they are terrified of rocking the boat or disrupting their corporate underwriters.
Just like earlier today, with their anti malicious javascript features[1]; they could look into empowering the users and changing the structure of how js is run in the browser. But that might threaten advertisers, so instead they opted for a clumsly blacklisting solution instead.
If you want an accurate heuristic for predicting Mozilla's behavior, just ask "What would Google want?". It may not be Google in particular that these decisions benefit, but they absolutely benefit those entities that are locking down and siloing the internet.
[1]: https://news.ycombinator.com/item?id=19614808
