[MrResearcher]

Because DOS relied on BIOS interrupt 10h to handle I/O:

  mov si, GREETINGS_STRING
  print_loop:
    lodsb                  ; Load next byte into AL, advance SI
    cmp al, 0              ; Check for null terminator
    je done

    mov ah, 0Eh            ; BIOS teletype output
    mov bh, 0              ; Page number = 0
    mov bl, 07h            ; Light gray on black in text mode
    int 10h                ; Print character in AL

    jmp print_loop
  done:
    ...

  GREETINGS_STRING db "Hello, BIOS world!", 0

And linux doesn't rely on BIOS for output I/O, it provides TTY subsystem and then programs use devices like /dev/tty for I/O. Run $ lspci in your console: which of those devices should the kernel use for output? The kernel wouldn't know that and BIOS is no longer of any help.

[zozbot234]

> which of those devices should the kernel use for output?

Whatever facility it uses for showing kernel panics, perhaps. Though one could also use IPC facilities such as dbus to issue a prompt in the session of whatever user is currently managing that media device.