Telling other people to never sell is a very dangerous and irresponsible move. This is a bad move because if the market does in fact become a true bear market, many of those who hold alts will lose 80-90% of their portfolios.
Being a bag holder is a real thing, and while I don’t think the term applies to btc and Eth, I do think it’s dangerous to bag hold the much more volatile coins.
In 2017 I bought several coins and held them, which have still not come close to their previous all time highs.
Everyone needs to make their own assessments and not be bullied into HODLing forever, because that is a legit decision you should let others make.