If lack of near unanimous consensus on a major decision is enough to kill bitcoin, then bitcoin was never a good idea to begin with.
Bitcoin was designed with the assumption that there will be major decisions that must be made even in the absence of near-unanimous consensus.
Protocols, not just bitcoin, don't work in the absence of consensus. One peer expects certain behavior from another peer, and if that isn't the case, the protocol doesn't work as intended. You can't have one peer saying that the block size is X, the other saying no it is Y and the block is invalid, or that the number of coins is A and another saying no it is B trying to invalidate A.
In order for protocols to work properly, practically everyone using them has to agree on what is valid and what isn't valid behavior. If a modified http or smtp server uses messages that a client doesn't understand, a page won't work or an email won't get sent. That's what's at stake here, hence the incompatibility of the various "implementations", hence the possibility of forking in at least 3 incompatible coins (the stalled chain, a BU chain, a BTC-different algo chain). If this proceeds, then any disagreement can be used by bad actors in the future to create more and more forks, until BTC becomes a joke.
The primary issue that needs to get fixed in bitcoin is not scaling. It's removing the possibility of contentious forks through "disagreements", which represent an open attack vector against bitcoin itself.
As for the price action, it reminds me of the 400 range when the prior fork FUD was ongoing and people were like "who bought at 380, price should be at 200 or lower".
You and I are using the word "consensus" to mean different things. You are saying (and I agree) that every peer in the network must agree on what is valid. In that sense, bitcoin requires, and in fact bitcoin currently runs on, 100% consensus. What I am saying is that right now the community has not reached "consensus" on how to scale. My point is that Satoshi's original vision did NOT assume that hard forks were impossible. Satoshi did NOT assume that everybody will always agree on the future direction of bitcoin. Satoshi did NOT assume that everything will be roses and that we will all get along.
In theory, the possibility of a contentious hard fork has always been part of the plan. If a contentious hard fork is enough to kill bitcoin, then Satoshi's vision was doomed from the start. I believe Satoshi's vision was not doomed from the start, and that a contentious hard fork will not kill bitcoin. But if it does, then we may as well learn it sooner rather than later and so we can focus our efforts on a modified governance mechanism (dash being an example of a modified governance mechanism).
If the first time that a contentious hard fork actually happens is 15 years down the road when everybody is using it, it would be very reassuring to look back and say "remember that scaling-debate contentious hard fork? We all thought it would kill bitcoin and it didn't. Therefore, no need for a worldwide economic panic this time."