The post clearly states that users can install extensions through the developer's website. The main difference here is that extensions cannot be silently installed — users have to explicitly install them.

Sounds good to me. No more annoying adware extensions.

I agree regarding adware, I think its just a poorly written post in terms of clarity. It could have been better summarised as

We are removing sideloading (The ability to silently install extensions from your local machine as an xpi file)

- This will not affect the ability to manually install extensions, they will need to be installed from a source code directory (Link to chrome post on same)

- This makes users safer (Malicious extensions will need to be approved and installed by a user)

- This makes it more obvious when an extension is installed (Confirmation dialog)

ETC

Thanks for making me read into it further

> Saying "To give users more control over their extensions, support for sideloaded extensions will be discontinued." Also seems disingenuous at best...

Isn't this how distributions install browser extensions from package repositories? Now I can pacman -S an extension. With this change I will not be able to.

More control, right.

Presumably pacman -S will still work, but on first run, Firefox will then ask if you really want the extension installed, listing it's permissions etc.

I think that's pretty fair. Lots of other software that interacts/loads into another bit of software requires manual configuration.

I guess distributions may be able to build a Firefox version that would load extensions installed using the package manager without prompt.