I think bitcoin makes on sense at all.
A decentralized money means every client holds a central bank -- it's feasible only for a very small scale. The block chain is 10G today. It can grow up to 100...0GB if it wants to get the same position as usd or euro or cny -- obviously it's impossible.
Am I wrong?
I just bought a 64GB SD-Card for $20. Enough for a much bigger blockchain.
Yes, you are wrong.
$20 is not cheap enough (for me), I believe 64GB will be too small for soon, and sooner in the future. The other problem is it takes several days to download it (~10G). If more people use bitcoin, maybe we need millions of years to download it.