1) Why not ? Look at Ethereum, Ripple, Litecoin, Dogecoin etc...
They are still here with and has survived previous crypto winter.
2) bitcoin survives every crypto winter because people has a lot of trust on it. This is what keeps it from going too low.
Other coins find it difficult because the owners/project team run away with the money when winter strikes them or find it too difficult to keep the project running.
There might be other reasons but these are common.