Just copying the comment I made when closing Clancy's bug, so more people see it:
I disagree. In the quiz, the maximum mark actually belongs to the 'slot' in the quiz, equivalently the column in the quiz grades report, not to the question.
There are other activities one could imaging, using questions, where it would make sense to randomly mix questions with different maximum marks (e.g. http://tjhunt.blogspot.co.uk/2011/09/what-i-want-to-build-next.html), but the quiz is not that.