This is not a "Dell-specific BIOS hack". Dear child, ask your folks about
PCs. I think it was only this decade that PCs would actually boot
*without* a keyboard. EVERY PC EVER MADE before would not.

Nah! Every BIOS since I remember (at least from 1990) had a choice on
the first page, Standard BIOS Setup. "Halt on all errors, Halt on
keyboard/video errors, Halt on no errors". At least these three were
always present.

Of course the default is always "Halt on all errors". Unless you modify
the settings on purpose, that's what happens.