I now understand your reference, the comparison the Bass' original design has been discussed numerous times in other threads. The trick of course as you so astutely point out is writing a driver for it, which few on this forum are interested in, or capable of doing.
While the 128K ROM might have been the "correct" way to do it, adding the 128K ROM is also arguably the "correct" way to add HFS support, and an external drive of any kind to the original Mac, not to mention that SCSI was a much more optimal format for the Mac than whatever the HD 20 drive is. However, that did not stop Apple from both creating the HD 20 and writing a software driver to use it with a 64K ROM. Wouldn't it have been easier to simply offer a ROM upgrade for the 512K Mac in September 1985 to allow the Mac to boot from the HD20, as well as natively use HFS? I think the "correct" answer is "yes". Morever this would fit with Apple's M.O. - how much more would power users have paid to get bootable ROMs for the HD 20? And then in January Apple could have released revised ROMs, with the 800K disk driver and SCSI, and charged those same users again for another ROM upgrade, which the die hard "brainwashed" Apple devotees would have happily ponied up for despite the price. Perhaps they could have avoided the 2 ROM revisions to fix the SCSI bug too.
As for being "completely pointless", that may well be in the real world, but as an exercise in vintage Mac tinkering, it has a much validity as any of the other proposed hacks on this forum. If Apple did it as an "official" solution to a similar problem in 1985, and John Bass did it unofficially, then it's just as valid an experiment today as it was back then, whether it is the "correct" way to do it or not.