Decentralized _operation_ might be ok but decentralized management and oversight seems to have not worked out. "Market Forces" don't seem to produce good architecture.
As far as I can tell the biggest problem with Bitcoin right now is the high transaction cost, which happens because it's not worth it for miners to validate transactions unless you essentially bribe them. If mining were more lucrative on its own, this wouldn't be a problem, but the reward rate for mining is hardwired. So in this case I'd say the problem isn't caused by the market but rather by the hard-coded nature of the monetary policy and the fact that there isn't a good process to change such core matters.
No, the high transaction costs are because the blocks are too small. As the currency has grown in popularity the volume has increased but the blocks have not, therefore the competition to get your transaction into the block has grown and market forces means prices have increased because of it.
Still the argument that "high transaction costs are because the blocks are too small" doesn't conflict with the argument that there is no easy way to change the code running bitcoin's blockchain, and in fact the latter would allow the former.
No, forking bitcoin doesn't change the code running bitcoin's blockchain. Carefully re-read what I wrote: "no easy way to change the code running bitcoin's blockchain".
