Crypto is a investment class which is high risk, and highly volatile. Most folks, even 'mature investors' are not adept at dealing with either high risk or volatile assets.
They may have high risk as part of their portfolio, but generally a very small amount, and not requiring active involvement to maximise gains.
Most investors do not deal with highly volatile investments, which require constant monitoring so as to react to changes in market conditions.
As a highly volatile investment, crypto is not linked to other volatile standard assets and most investors are not tuned to being alert to factors which may trigger a change in the sector as these are outside regular investment parameters.