Why can’t I import my Bitcoin Core private key to an Electrum wallet that supports Lightning?

Why can’t I import my Bitcoin Core private key to an Electrum wallet that supports Lightning?

running importprivkey In the Electrum console you get:

Error: This type of wallet cannot import private keys. Try creating a new wallet with that key.

When I create a new Electrum wallet using my private key, why is Lightning disabled for that wallet?