It also recommends you change your locks so no more thieves can get in, in future. If it weren't for the extension, you won't even know someone entered your house, let alone they did something bad.

I would notice no matter the extention. Again, I've been working into the IT for 27 years and don't need a reminder. A tool must tell me where an attack comes from, not to warn me to choose a strong password (which I already do). What is useful for such a tool? Only to annoy people?

I'd like to add that the extension also gives you a notification if your account got successfully logged into from a new IP. I like to think that is useful to some extent. :)

The tool is not entirely useless. It at least makes you aware of the attempts, and encourages you to use strong passwords.

Because not all cases of failed login attempts are "willing attempts".

I wish to add an opinion on the legal aspect.
In Italy (but I'm sure that this is the same in many countries, too) both attempting to force an IT system with false / stolen credentials and attempting to steal credentials from someone are a crime. I am surprised that the IP disclosure feature has never added since the begin and I am even more surprised that someone might be worried about issues of IP privacy of someone who willingly is trying to force illegally a system. Rather than suggesting to experienced users that work in the IT field to change their password, give them the ways to identify and to report to the police the attempt of intrusion.