Why do you think there should be a correlation? Amount of mastercoins being transferred is encoded in a different way. Bitcoin amounts are irrelevant.
Of course there needs to be a correlation.
Are you absolutely brain dead?
Bitcoin amounts are the only thing that is relevant.
The depth of the cluelessness here is astounding.
Ask yourself, "Why do you think the correlation is unnecessary?"
Because if it takes 0.001 or 0.00001 BTC or whatever amount why should it matter when I'm just encoding in the blockchain to move X amount of MSC from address A to address B. Using BTC is just a way of getting the message in the blockchain. The actual BTC don't matter as obviously people are concerned with just moving MSC around.