I see.
there is a difference between wilful poor form requesting a push/taxi when you're not ready to beat someone else to the punch and an error (potentially dangerous) like taxiing away before it's safe to do so.
I would suggest that if pilots are deliberately getting out of sequence by requesting a taxi before the engineer disconnects it could lead to a occurrence where they actually taxi with someone attached, a dangerous mistake that
VB made once in its infancy to much cries of "pay peanuts/get monkeys" etc. No harm done but it was an inadvertent procedural error