The only reason why a new PoW coin would become popular is if there are many people who really prefer Proof of Work, but who would that be other than miners? They won't be able to afford mining long if they can only sell the coins to other miners, as mining will then always be something that costs miners money, as the only way for them to make money as a group is for non-miners to buy these coins.
There does seem to be some stickyness between coins. A bit. A lot of crypto is just simply speculation. That's why there are altcoins that have enough value that it's profitable to mine right now. It's really not hard to see a PoW coin getting hype behind it simply because it's PoW.
