I wonder if it would've been better to use contact heads (connected to something like a Kryoflux) and spin the disk much slower, thus preventing more damage from occurring in the process. One of the first things taught in data recovery is that you should never put media which is known to be physically damaged into a drive and attempt to read it that way...
I think the big reason they didn't do that, is that the hardware like that just doesn't exist. It'd probably be possible to engineer something that could do it, but the question is what's the cost of doing that vs attempting to throw a head or two at it to recover the data? They looks like they're much more physically substantial/robust compared to modern heads so it might not be as big a deal. If you end up further damaging the media though it might be a bad thing. But the question is, if it's that delicate of media (flaking off, just scratched to hell, etc.) were you ever going to be able to recover it at all anyway?
the heads were more durable, to be sure, but the SCREECHING a disc would make when one crashed... it was loud. I used to have a spare 14" platter that showed the gouges. Car brakes don't get scored that bad.