Wow! Quite astonishing really. I do apologise for making the incredibly rash assumption that your use of the nickname "Sr Consultant" in some way implied that you might be, or percieve yourself to be, a sr consultant. Quite a schoolboy error on my part.
That out of the way, it's not arrogance that has led so many existing management consultants to come back with a mixture of groans and withering responses - it's disappointment. Now that we understand the context of your question I think it makes alot more sense. It is of course a trick question used to weed out people who aspire to be a management consultant, yet have no real understanding of what we do on a daily basis (it's all powerpoint and excel - right?). Its not a question that would be asked of anyone who has already shown a clear understanding of what consultancy entails.
The correct response is something along the lines of:
"both are useful tools that are worth mastering - excel for analytics and number-crunching, powerpoint for visual support when presenting complex issues, plans, etc; that said they are simply tools. Being a wizz on excel is only useful if you understand the mathematical dynamics of the issue at hand, and while a bad powerpoint presentation can undermine good content, a multi-colour, 3D deck does little to hide poor content. Lets face it - both are packages that can be self taught to basic competence and both can be taught to professional level in a week or so in a classroom".
If you gave a response along those lines, then you should be fine.
If you tried to actually make some sort of silly rational arguement in favour of one or the other, then you're well and truly *%££ed.
Of course if your conviction that MC's are "down right arrogant, shallow, full of themselves and stupid" came across in the interview, then its all a bit academic.
PS - Can you guess why I use the nickname Wowser?