If we split into two and there is a significant dispute about which chain is Bitcoin, market participants may give up and divest.
1) Fork futures trading ensures - well in advance of the split - that there is no dispute. In fact, if the market caps in futures trading were so near equal that there could be a dispute (from the typical bitcoiner's or general public's perspective), and the market deemed that a problem, the market would tip toward one or the other. The market won't do anything dumb, at least over time; that's the whole idea of Bitcoin in a sense.
(I know this is only true in the forkist view, opposite to the one you probably still hold. The point is all the pieces of the forkist worldview fit together coherently as well. You kind of have to try them all on for size at once to evaluate the paradigm.)
2) "Investors may be confused" only applies if there are two persistent chains that are nearly equal in value. If there is a major difference, the minority chain will just be ignored in most cases, by most merchants, etc. It will have a little niche community. If this seems unrealistic, just realize that it seems that way exactly because it is highly unlikely the market would make two persistent chains with any significant value in the minority one. It is even more unlikely that the market would allow for two chains of nearly equal value, partly
because it would confuse investors (if it really would; I trust the market to decide that more than my own judgment).
In other words, the simple answer is, "If it's a bad idea to have two persistent chains, the market wouldn't do that." If this makes the market seem like too powerful an intelligence, note that this is already the intelligence that Bitcoin relies on to maintain its value anyway (the purple text above applies here again).
Let me try and put it this way then.
Which attitude do you think is better to ensure long term success? Being paranoid about vulnerabilities and fragility, and always looking to improve resilience. Or being complacent and overconfident about the strengths of the system? Which is the side you would rather we lean towards? What is more healthy?
The truth is of course that we need balance. People like GMax have played an extremely important and crucial role, in identifying risks and advocating a cautious stance. Please respect that this is a valid and important part of the community.
I very much agree that people like Gmax have their place, and caution as a general heuristic is great - it is great to have a plurality of views for the market to consider, all debating furiously. The harrowingness of the debate makes it feel hopeless, but in fact that is the very thing that should give us hope. We should only feel things are going south when people barely lift a finger to debate anymore and people aren't angry and vicious and weasley.
The problem right now is that people like Gmax have too much power, because enough investors conceptualize the situation much as you do, which goes hand in hand with more reliance on a central group of devs to help keep consensus (I know it's not necessary and you are open to Classic with 95% threshold, but I see a strong connection in the minds of many).