Not a bitcoin maximalist per se(though a huge majority is BTC), a shitcoin is simply a coin/token that is either:
1. Unnecessary: A perfect example would be Dentacoin. A coin for dentists? wtf?
2. A scam or a pump & dump: No explanation needed honestly. e.g. Verge(XVG)
Lol. A coin for dentists? What is next? A coin for chickens - Chickencoin? In my opinion, majority of the cryptocurrencies are basically shitcoins while only a few are legitimate.
So many shitcoins died after the 2017 rally thanks to the prolonged bear market, but more were created to replace them. Its basically a never ending cycle.