What good are your altcoins when the developers/miners give up on the project? A bar of gold is always a bar of gold, no matter what the price of gold is.
Bitcoin could hypothetically be replaced by Dogecoin and bitcoin would have no value.
A cryptotoken is still a cryptotoken as long as the network is propagating tx & blocks. The whole point of them is that they continue to function regardless of if the "developer" is around.