Because everyone is adjusted to thinking cold wallets are the only hardware wallet.
This is a new storage technology. The key is generated only at the instant it is needed for a transaction; the memorizable phrase leads to its momentary generation.
Wallets can be hacked. Hack is this sense means accessing the wallet without knowing the seed. However, when a cold wallet is hacked, the key is exposed; when a Bitfi is hacked, the key is not exposed because only the key leads to its momentary generation.
Hope this clarifies.