and why a whole blockchain system has to wait when or if Jihan wake up in a good mood, [...]
One thing that is left out of your argument, and left out of the argument of many of the so called 'Bitcoin experts' is that the miners as a whole have very real incentives to do what is best for Bitcoin, including when deciding if they will signal for a particular fork/proposal,
and if/when there is a serious threat to their ability to continue mining bitcoin (such as a serious threat to change the PoW), they have substantial incentives to not act in Bitcon's best interest (they have incentives to act in a way so that they can continue mining bitcoin, even if this means acting in a way that will damage Bitcoin over the long term).
When a person buys mining equipment, they are essentially paying a bond to the manufacturer that they will use their mining equipment in a way that is not harmful to Bitcoin over the long run. The reason for this is because ASICs have no other use than for mining Bitcoin (the actual use of Bitcoin ASICs is
slightly more broad, however I do not see any reason why any other crypto would want to use the same PoW as Bitcoin as this would likely expose them to significant security vulnerabilities), and that mining equipment will have net revenues that will only recuperate the cost of purchasing said mining equipment over very long periods of time (it is also noteworthy that, as a general rule, as mining equipment has recouped a larger percentage of it's purchase cost, it will have less of an impact on the overall network due to both advances in technology and additional purchases of other mining equipment).
Mining pools provide their services of pooling resources together in a way so that variance is reduced, and recently either take a stance on various political issues, or allow individual users to take a stance on various issues. For the most part, pools collect fees in exchange for this service. If a pool is acting in a way that is contradictory to the long term interests of Bitcoin, then miners will point their equipment elsewhere.
The above causes trust to be placed onto the manufacturers of mining equipment, however the manufacturers of mining equipment have incentives to act honestly (as defined as selling their equipment at a price that is not below fair market value), because they are essentially paying a bond in the form of the costs of manufacturing their equipment (generally fairly low), and the costs of R&D of their equipment (generally fairly high). Some mining manufacturers will use their own equipment, which results in them paying the above "bond" to themselves, however they would still need to pay the "bond" described in this paragraph, and has incentives to earn at least as much mining revenue (plus capital costs - eg, interest) as they would get if they had sold the equipment to the public. Mining manufacturers also will care about Bitcoin over the long run, because in order to recoup the R&D costs of designing/manufacturing mining equipment, they need to sell their equipment over fairly long periods of time.
The engineers that are hired by the above mining equipment manufacturers have fairly transferrable skills, and if they are not offered a high enough salary by a mining manufacturer then they will simply find work elsewhere. The market for these kinds of engineers is generally very competitive.
It is for the above reason why the miners as a whole will act in the best long term interest of Bitcoin, and can be trusted to do as much. The scope of when a miner should signal for a particular proposal is entirely up the individual miner, and the claim that miners should signal for a particular proposal when they are ready to implement said proposal is made by those with self-claimed expertise of Bitcoin, with self-appointed authority over Bitcoin, and contradicts with the above, as this does not necessarily mean that a miner would be acting in the best interest of Bitcoin if a proposal was not in the best interest of Bitcoin.
Node count is very easily faked, and it is fairly easy to fake economic activity, so it is very difficult to use either of these as a means to measure if a proposal should be implemented (the same is true for essentially every other measurable indicator). As a result of my above argument, a better measure to determine consensus is signaling from the miners, more specifically, that the miners are signaling for a proposal that is (a) in the long term interest of Bitcoin, and (b) in the miners' good judgment, there is a consensus for a particular proposal -- if both of these criteria are not met, then a proposal should not be signaled for. I would argue that this would roughly fall in line with Satoshi's whitepaper and early statements, as his whitepaper made statements assuming that miners would act in their own economic best interests.
Before something like this is added for any particular softfork, I'd like to see a detailed investigation into how much of the economy is committing to support it; how much is actually doing verification rather than just blindly trusting miners; the popularity and expected behavior of each end-user wallet software; etc.
At the end of the day, this is essentially 'proof of bitcoin.org/bitcointalk.org and I would note that both domains are heavily accessed partly because they are sites that Satoshi originally built and posted on.
