I think the choice of the IBM printer port were determined by costs.
I just checked the PC (not XT) reference manual, and the mochrome/
printer adapter card uses a single 7405 for all the device control lines.
These lines come from a latch which is cleared by master reset.
Might have cost another chip to change it.

A more interesting question is why the port was not made bidirectional.
All the gates are there, and if an unused latched output had been
connected to the output enable on the driver -- a no-cost change --
we would have had an 8 bit bidirectional port with control lines.  Slow
(because of the caps on the data lines) but much better than what
we have been stuck with since then.

Mike Mullen