As with most comments about most of these things, you have a very skewed view of the average user. The vast majority of people, even those using Firefox, will not be aware of this. And many that are aware won’t care to use it. It won’t make a noticeable difference unless it’s made default, and even then Firefox only has a small percentage of the browser market.

I don’t understand how people like you seem unable to think past your very first reaction, you don’t need deep knowledge or anything to figure any of that out.