Spreading things around really helps. Putting money into good sound projects is what is the best approach in my opinion. Knowing not all will succeed, we need to leave some margin of error.
Personally, I am not in the Bitcoin is dead camp. While it is not a huge part of my portfolio, I do hold some because I believe it will be higher than it is today. I do not think that it ending up in the $50K+ range at some point is off the charts.
Many of these blockchains will go higher...not all will explode...but many will go higher.