you are probably right it is doomed to fail but not for the reason you mentioned.
imho here is why
1. reliance on internet. if some global cataclysm happens it might dissolve. for example what if governments start to tax any traffic that goes across the border? or something similar happens.
2. no solution for growth. there is no even talk about getting rid of having to store all the transaction on each node's medium. how can it grow when there is no space to grow into?
3. big players will never adopt bitcoin because they will never rely on a handful of individuals who control the source code. even though adepts claim bitcoin to be decentralized, most (all?) crysises were solved by centralized authority that de-facto controls the source code emission.
1. Yep. If the internet goes, so does bitcoin. I don't see how a "border" tax could work however. Your google search for a local barber could cross into many countries.
2. There are many solutions to this "problem". Wallet software does not have to DL the entire blockchain. Mainstream wallets of the future may be cloud based or use pruned trees instead of the whole chain.
3. Huh? There is no center. Do you mean the qt wallet? You could write your own software and not answer to anyone. The protocol is open source and anyone can use it however they wish. Gavin and his team are looked to because they have been at it for years, but anyone can trump them if they have something better.