The real problem lies in the fact that that that guideline does not apply in this type of situation. That guideline is for pages of options, not for a tabbed document interface (as an implementation of multiple document interface). There is no interface guideline for multiple document interface, much less mdi via tabs.
Yes, it's definitely the HIG that is the problem. I would point out that none of those apps follow the HIG anyway. According to the guidelines, if there are more than 6 tabs, you should display a list control instead. http:// library. gnome.org/ devel/hig- book/stable/ controls- notebooks. html.en
The real problem lies in the fact that that that guideline does not apply in this type of situation. That guideline is for pages of options, not for a tabbed document interface (as an implementation of multiple document interface). There is no interface guideline for multiple document interface, much less mdi via tabs.