I think his advice is mostly targeted at new investors entering the space. Ones that likely don't have the technical knowhow to do the kind of DD you are talking about here. For that reason, telling them to buy bitcoin before they buy anything else makes a lot of sense. You may be right though that you could in theory build a solid portfolio without any BTC exposure. Though, I am in the camp that believes BTC will be one of the major players for a long time. Whatever it lacks in tech currently, there will be ways to upgrade/update it.