214/8 and 215/8

These were delegated on the return of nets 49 and 50, along w/ about a
/9 of mixed /16 and /24 space. e.g. an overall reduction in the
amount of space. Jon Postel, as the IANA, approved the transfers.
At that time, ARIN did not have control over legacy delegations.

So I seem to be missing something that keeps me from understanding this --
why didn't they just turn off the /9 of mixed /16 and /24 space and
keep the two pre-existing historical class-As, which would have more
fully followed the BCPs?