All the experts mentioned are anti-Bitcoin advocates so you don't expect them to say you should put a higher percentage of your investment in Bitcoin, yeah definitely they will advise new investors to look in the direction of their traditional investments. So as long as you are investing what you can afford to put aside for a long term into Bitcoin, you are good to go through with Bitcoin volatilities because of the long-term perspective of the investor.
The why people advice others to not invest their higher percentage in the bitcoin is the time bitcoin has not gotten firm, and now that bitcoin has gotten firm I can advice you to put your large investment in bitcoin...as of that time many of them does not believe that bitcoin will last to the extent that bitcoin will stay on track up till today..currently it's obvious that inflation is affecting traditional business now, so it will be good that you invest on a decentralized currency that you control without anyone monitoring it for you, let me use myself as point of reference, bitcoin investment is something we need to understand that the higher amount of capital you invest is the why the profits will accumulate during a bullrun.