As a user, I think Chrome ignoring autocomplete=off is great and if it was a flag, I would enable it without hesitation. This feature is misused all the time.
It may well be that disabling autocomplete is open to abuse, but it's not up to the browser venders to police the quality of webpages. There are plenty of other features that are abused all the time. Should browsers disable window.onscroll because it can be misused? How about all of JavaScript?