- miners: they bear the biggest costs and are responsible for the security of the network. Without miners there would be no bitcoin.
- economic nodes: nodes that have real activity going through them that relay transactions and accept or reject blocks that miners provide them. Coinbase's nodes are significantly more valuable than my personal node for my wallet.
- core dev team: their power is soft but integral, no-one wants a chain that can't be updated over time.
Owners of coins currently have little to no influence.
If all/lots of the miners pulled out, then wouldn't the work factor decrease so that regular people could run it on their desktop machines? That is what happened at the start of bitcoin, right? Are miners that required?
Yes, we need miners. But yes, you're right, the difficulty is adjustable, so ultimately either we need miners[0] or we need miners[i].
If there's any value to be had for a coin and the PoW matches existing hardware, it's likely that miners will show up.
other people would start mining-- botnets, gpu gaming enthusiasts, people with excess FPGA capacity, etc. and then these people would become miners.
Because that difficulty factor changes over many mined blocks, if the ASICs all suddenly stopped mining that chain, there might not be enough hash power to ever find another valid block.
And until so many blocks are found, the difficulty won't change, so the chain will be fully and completely dead (at least on the scale of months)
For a rough idea of the scales, just look at the current reward for finding a block (12 btc) and it's current value (about $31k USD). Miners are just barely breaking even on ASICs, so a $31k miner should be able to pay for itself over it's lifetime.
So unless you have hundreds of thousands of dollars of miners, you aren't going to realistically find a block, and unless you have millions of dollars of ASICs you aren't going to be able to mine enough to keep a chain from dying on your own.
Some alternative crypto currencies use algorithms that supposed to be really hard to do in ASCIC, I suppose those would be more feasible for rel people to use them, but as I understand we are stuck this way with bitcoin.
It's been around a long time and bitcoin hasn't been changed to take advantage of it.
Ultimately, the community seems to have a big say in bitcoin and it's not limited to a proportional share. The community includes at least {holders, merchants, miners}. It's in their mutual interest to preserve stability but if one group acts in their exclusive interest to the detriment of the others, it makes sense for the others to consider a fork.
> I was wondering, why the bitcoin owners themself cant't decide. ... should have more to say about it.
Ultimately that sounds a little aristocratic and bitcoin itself seems more egalitarian. Regardless of philosophy, the blockchain is defined to be a consensus of a set of computers running software. Anyone of us could write new software to take the bitcoin blockchain into a new direction with new features. If we could convince some folks to run our new software, we would have our own fork. If the features are compelling enough, we could take the majority of nodes with us. Decentralized and fairly democratic -- you can have your blockchain and we can have ours.
Of course it hasn't, Bitcoin is decentralized and Peercoin requires the developer of the system to continually sign the chain.
Proof of stake sounds lovely, but it doesn't work and attempts to rescue it have at best resulted in things with very different security assumptions and properties from Bitcoin. https://download.wpsoftware.net/bitcoin/pos.pdf