I think it is possible to explain the current situation in simpler words and take the right decisions based on the current state of the cryptocurrency market.  I would never sell Bitcoin either, or even if ETH were the most popular coins, not only in the near future, but also for a longer period of time.  But to buy more profitable altcoin, in order to sell less promising altcoins, you need to audit your portfolio and buy more promising in your opinion.  I think every user of cryptocurrency will make the right choice and benefit from it.