The goal of cryptocurrencies is to remove humans from as much of the equation as possible. An ideal cryptocurrency will continue functioning as long as people mine it (and the internet works).
Yes exactly. And I'll add that when humans are involved, it should be through as few centralised intermediaries as possible. Here BIP 100's hash power mediated block size limit change mechanism is superior to the hard fork block size limit change mechanism, which is highly dependent on a small number of influential developers.
One might argue that pools are analogous to centralised intermediaries that will control the limit under a BIP-100-like regime, but hash power generators can point their machines at any pool they want, which transparently provides feedback to pool operators on whether they're serving their hash power generator well and provides them with a powerful incentive to do so, so it's really hash power generators - broad class of people for which there is no political barrier to entry to join - that have the power. And unlike the hard fork process for changing a consensus rule, pool operators don't need to download new software to express their will to change the limit.
Indeed, it can remain static, and it will eventually become locked in. At some point it will be locked in, and we'll be stuck with whatever was last agreed upon.
Yes, and the danger is that when the Bitcoin protocol gets locked into a particular state, it also locks in a block size limit that is too low or too high. BIP 100 or some variation of it solves that. The protocol can reach a final state, and still have its limit fine-tuned, in response to changing market and technological conditions, by the community.