Best Answer - Chosen by Voters
It's scrambled because it's meant to be paid for to get it unscrambled. The card you will receive (or activate) would have a code on it. This code is the password, and to scan through each and every combination will take you a while.
The reason why they scramble it in the first place is because they are not going to charge if anyone can view it, and they're not going to use an easy code because it'd be pretty much anyone can view it.
Now if everyone had this way of unscrambling it, that'd be good, wouldn't it? Except then Multichoice (or other TV suppliers using similar technology, such as TopUp TV) would lose out on money. Then they can't afford to provide the channels. Then there'd be nothing to unscramble.
They need the money to continue broadcasting. You wouldn't expect to walk into a shop and walk out with goods without paying, would you? How can a worker earn a living if they provide their services free of charge?