My exchange still has enough bitcoins to cover 95% of deposits.
What's the big deal?
It's not like 95% of customers are all going to try and withdraw at the same time.
My employees worked really hard and deserved a Christmas bonus. Not to mention, we needed new office furniture.
What you're describing isn't what "going fractional" actually means, what you're describing is just petty theft. Fractional means that you are leveraging deposits to make a return.