Bubble concerns worth listening to on crypto usually talk about the price getting to far ahead of the tech, network congestion, tx volume, scaling solutions, hard and soft forks, governance challenges, and regulatory uncertainty.
Bubble concerns not worth listening to talk about lack of transparency, the fact that not backed by anything, hacks, and of course tulips.
Since I can't view the WSJ Economist Survey crosstabs and filter on valid opinion vs hot take, I feel safe ignoring this result. While they're probably right, they're also probably right for the wrong reasons.