I like the term a lot. However, popup blocking is actually a real feature since sometimes you want to block popups and sometimes you don't. Designing a system that makes sorting out allowed vs. disallowed in a user friendly way is non-trivial and is in fact a feature of a browser. It's especially a feature if enabling means, as it did for the Internet Explorer team, going back and changing old functionality to allow for blocking.
I'd call it an anti-feature at the browser API level. Code to launch a new browser window is nonessential and it was included as a feature long before anyone thought about whether it was a good idea for the product as a whole.
Today, popup windows are an accepted feature, though still insanely overused. The only time I have ever found popups at all valuable is for instruction annotations during stateful sessions where winding up in a situation where the 'back' button is needed is undesireable. I would still usually prefer to simply open a new tab.
Ok: one other time, this web application at my last company had a subtle bug where putting two consecutive slashes in the URL of the login page caused weird things to happen. Their answer was to launch the app in a popup window with the correct URL.
I think if it had been always impossible to launch popup windows by default, then websites would be generally better designed.
