> this is necessary for security

Why? You can't read the source of this addon and evaluate whether or not it should have this access? This should be a permission that you can grant to an addon, we're not children that must at every juncture be managed so they don't burn their fingers.

No, almost nobody can read the source code of every addon. Even the people who can won't be able to spot malicious behavior unless it's very obvious.

Can you evaluate the source at every silent update?

Then maybe updates shouldn't be "silent" and it should be easier to install a zeitgeist-approved old version.

Or you can not update things silently, because it's a terrible idea.

Some browser users are literally children.

Children are everywhere. They shouldn't drive cars, so we don't let them. If they shouldn't manage browser plugins, we shouldn't let them. This is really incredibly immaterial to the point - which is that browsers treat everyone like they have some sort of mental handicap.

In a competitive market, which browser is going to win, the one that says "no one under the age of 16 can use this browser because they're too likely to fall victim to the security holes we intentionally didn't fix" or the one that says "we fixed that security hole"?

I actually use a vim-style plugin in Firefox and this seems obvious to me, how do you think the majority of users feel?

Clearly then, all tools must be designed to only support the least common denominator.