Just for your information, the Ribbon (and the whole window management) is implemented using a third party library. We can know this by using some tools (e.g. Spy++).
So I would say that all the behaviour related to the Ribbon is defined outside the Sparx developers. You may say that they should change the behaviour, but I think they should concentrate on their own code and it is a nice solution to buy 'existing' features, even if they are not perfect for all of us.
You might also say that they should choose the 'perfect' library for everyone and every situation, not just at the time of selection, but in the future. I agree, if that is possible.