I would help the questioner create a multi-faceted framework to manage the assertion that Bitcoin is a speculative asset – rather than deny that it is speculative.

A - Risk management:

Acquire a small position in Bitcoin e.g. 1% of your net worth. Thinking in decades, if Bitcoin proves to be as good as we currently think it is, it will probably grow to a substantial portion of your net worth. If it goes to zero, you won’t be financially ruined but at least you can tell your grandkids that you tried to make the world a better place.

B - Monitor adoption:

If the Bitcoin adoption rate flatlines or declines and the desired S-curve becomes a pipe dream, then Bitcoin should be perceived as more speculative.

C - Monitor existential threats:

Learn about what could result in the failure of the Bitcoin network and, if you are technically capable of doing so, understand what countermeasures and contingencies could prevent such a failure.

D - Monitor volatility:

Obviously, less price volatility would indicate that Bitcoin’s speculative nature has diminished – but this rule of thumb shouldn’t make us neglect point C.

Thomas Sowell: “There are no solutions, there are only trade-offs; and you try to get the best trade-off you can get, that's all you can hope for.”