He did not mean that one should expose the thing as an LBA-addressed SCSI device, but that the USB-layer always does it that way.
Which makes me wonder... are there SCSI enclosures for parallel ports? And if so, did they come with ASPI drivers? Because that would allow the DOS side to rely on the generic ASPIDISK.SYS, ASPICD.SYS and ASPITAPE.SYS drivers, while the other end just needs to handle the LPT <-> USB communication layer without much translation.