If you think frames are bad now, wait until you read this little nugget from 10 years ago.
Frames break the unified model of the Web and introduce a new way of looking at data that has not been well integrated into the other aspects of the Web. With frames, the user’s view of information on the screen is now determined by a sequence of navigation actions rather than a single navigation action.
Navigation does not work with frames since the unit of navigation is different from the unit of view. If users create a bookmark in their browser they may not get the same view back when they follow the bookmark at a later date since the bookmark doesn’t include a representation of the state of the frames on the page.
Even worse, URLs stop working: the addressing information shown at the top of the browser no longer constitutes a complete specification of the information shown in the window. If an author copies the URL in order to include it as a hypertext anchor in one of his or her own pages then that anchor will not lead readers to the desired view but to the initial state of the frameset. Similarly, if a user decides to send an email message to a friend with the recommendation to check out a page, then copying the URL from the browser will not work if frames are used since the URL points to the frameset and not to the current view (with the information of interest to the friend). Given that social filtering is one of the most powerful mechanisms for information discovery on the Internet, it is an utter disaster to disable the URL as an addressing mechanism.
I think I’ve discussed this before. It’s just funny to read something like this that was written 10 years ago. And, yes, frames were bad back then too.
[ Why Frames Suck (Most of the time) ] useit.com