So like the cops... it shows up only after the crime has been committed, and only protects some of the population (Google passwords) and not the rest of the population (e.g. your banking password isn't protected, because it's not a Google site).
Seems slightly less than useful.
I disagree.
If you use Gmail as your primary e-mail then your Google password is the crown jewel of your online identity, since every other site out there (including your bank) uses e-mail as the password reset channel. Sure it might be nice if the tool were more general-purpose (though that would require changing the hashing strategy, which intentionally uses relatively few bits as a security measure to protect against brute force), but if you can protect only one password, your e-mail password is the one.
For people who use not just Gmail but lots of Google services, it's even more critical. I store lots of important stuff in Drive, have my phone report my exact location, have my whole address book synced, etc., etc. It doesn't concern me to have so many eggs in one basket because I trust Google to maintain good security, but it can only be as good as my authentication. I use 2FA, but there's still value in being careful with such an important password.