BaurusdB

Have you 'studied' the economy of GTA Online? If so, what's your opinion on the changing online UX by introducing new units of currency by Rockstar meant as a "sorry our service sucked"-package?

The primary use of Bitcoin is its use as a medium of exchange.

but it seems that people have had their bitcoins lost or stolen

That's because people aren't storing their private keys in a secure way, it has nothing to do with Bitcoin as a protocol.

Companies like Visa and Mastercard have a clear monetary incentive to make their services unhackable.

Their services are not 'unhackable'. In fact, credit cards are one of the most insecure ways of transferring money online.

These companies just have an incentive to make them less hackable

I'd argue they don't. Obviously it needs to be 'secure enough', but with chargebacks and insurance, they don't really seem to care too much about robustness. If they did, I'd think they'd change the way credit card works, since it's been proven countless of times how insecure they are. This is just too costly, so they just leave room for a better form of payment (i.e. Bitcoin) to grow.

What do you mean by "unhackable"? If a user uses a weak password, his coins could get stolen. If a user uses weak entropy when generating an address, his coins could get stolen. But again, these are not 'faults' of Bitcoin, the protocol. An undiscovered flaw with the protocol could exist, but we obviously don't know of one (yet?).

An entity could get 51% and do a degree of damage, but Bitcoin would not be 'hacked'. The reaction of the market, however, will be the detrimental issue here, rendering the value of 1 BTC near-zero.

Anyone willing to contribute or able to audit the code, such is the beauty of an open-source project.

This is one of the most amazing aspects in my opinion. Try auditing the FED or the ECB.

If you have any other questions, I will gladly answer them. You can always find way more information in the Bitcoin FAQ.