I disagree with that notion.

Let´s take the example of Bitcoin. The value of a Bitcoin would crater if somehow the narrative
of a distributed, immutable ledger with a 21 million Bitcoin hard cap was changed to something different.

This happened with several altcoins. They had a certain use case and after seeing the success
of the privacy-focused coins like Monero or ZCash they suddenly pivoted their narrative to
also fit in this category.

I concede that it may be a feature of these open-source projects that they can change the direction
if new promising technologies emerge, but keeping an existing narrative also has its advantages.