Copycats? (Not really, since they brag about what's different) Small coins? (Still excludes eth, though it's getting there) Subject coins? (relative King Bitcoin, far-fetched for people who haven't heard that expression)
Hard to come up with a good name, I don't even think shitcoin is a good name as it doesn't differentiate between the outright scams and the well-intentioned projects. IMO, the latter is still unlikely to have a large adoption or value compared to BTC due to first-mover advantage and network effect, but there's a difference between trying to make money better even though not successful and to scam people.