In reply to cfc.

Putting an option in to turn this behavior off is antithetical to having the behavior in the first place. Providing the user with a choice requires them to make a decision that frankly, they shouldn't have to make. If auto-activating the module provides helpful functionality and doesn't break anything, then providing an option to not auto-activate it is a decision that your average user should not have to bother with.

I personally turn off most of the Jetpack modules, simply because I don't need them. I don't post LaTeX code, for example, so that feature is pointless for me. But I know what LaTeX code is and I turned it off intentionally. A user who turned off auto-activation at some point in the past, and then is told by somebody else to "paste this bit of magic code in to get a math equation on your blog" might be surprised and potentially frustrated when it doesn't work. They may not realize that this "option" that they didn't understand or care about from months or years ago is now impacting something else that they're trying to do.

If you're going to auto-activate new functionality, then simply doing it and not having an easy-off-switch is indeed the right decision. You can certainly argue about whether auto-activating new functionality is reasonable or not, but the decision to not put in an option for it makes perfect sense from a user's perspective. Don't give the user options they don't understand, need, or can make the wrong choice for without knowing it. Power users who want those options can add them via a different means.