Setting aside the issue of conformity, I'm pretty anti-menu bar myself. I  
try not to use them if I can avoid it.

For all the talk of menu bars being easier to use, I find them irritating.  
Functionality buried in submenus, trying to guess which of the menus has  
the option you're looking for--context menus being the worst, with  
functionality coming and going and you not being able to do what you want  
until you first select an item which is (often arbitrarily) associated  
with it.

Pfeh.

On the other hand, had there been a system-wide menu bar for Squeak, I  
would probably have been able to remember how to access SqueakMap the  
other day--unless it was context sensitive, in which case I would've had  
the same problem.