Why on earth would you store your value in any but the most scrutinized, monitored, long-running, stress-tested, brilliant dev-backed blockchain? I could see diversifying into a few alt-ledgers, but not more than a few, and only in proportion to their excellence in terms of dev team and track record. The rest would be speculation based on future promise, but that is even more limited. The marginal utility of each additional alt-ledger very quickly drops off.
The fundamental value in parallel blockchains each having a different hashing algorithm is that it mitigates some of the risk of one of the hashing algorithms getting broken. Altcoin software with such trivial tweaks can be effortlessly kept in sync with the latest bitcoin developments through build scripts, so I disagree with your dev-team and track record argument.
This argument is self-contradictory. If the tweaks are trivial, there's only trivial value (and unknown risk of harm) in using them. If they aren't trivial, dev team and track record matter. If the tweaks are useless or of unknown value/harm, there is no reason to switch no matter how easy it is (just puts your wealth at risk needlessly). If the tweaks are useful, known to be harmless, and can be effortlessly kept in sync with Bitcoin, they will soon be incorporated into Bitcoin. Also scrutiny and stress-testing and overall moment-to-moment monitoring will naturally gravitate toward the main blockchain.
If it were not the case, why not just re-release Bitcoin 2 - exactly the same as Bitcoin, but launched today? Then you could
really instantly incorporate all development changes from Bitcoin. And people would have a chance to be an early adopter all over again. That's all most of the altcoins are. They just offer a trivial tweak as a gimmick to get people to switch, since "there's a chance!" it might prove superior and become king.
In the end, when switching costs are trivial, even invisible to the end user like in the case of fully incorporated decentralized exchanges, it comes down to
who's maintaining your blockchain. If Bitcoin 2 has fewer people watching for slow orphan blocks and it's exactly the same as Bitcoin, only an idiot would have their money there (or speculators preying on idiots). And the more an altcoin gets away from being an exact clone of Bitcoin, incentivizing a possible switch, the less automatic dev support it can get.
The economics of blockchain maintenance/monitoring dictate that talent will gravitate toward the most important one with the largest market cap, as that has the most people's money on the line. Everything else follows from there.