Admins in particular like to (a) understand how things are configured and (b) avoid changing things (creates work and potential update conflicts).
MAC configuration is complicated, tedious, error prone, and seems to bite you in the ass with every update. All things that make a bad day for an admin.
I'm an admin. Have been for many, many, moons. I've found that when things seen to behave that way it's because I have failed to sufficiently adjust my understanding of them. Often, we can be guilty of expecting that everything should behave like the least common denominator set of features between all host systems. Often, there is great value in finding "the way" that a particular system is trying to exemplify instead of forcing it to match my own.
To be fair, that least common denominator set of features can be very powerful and capable. It's not a slam, I'm just saying that finding out the in depth method of operation for a given system can often be rewarding.
MAC configuration is complicated, tedious, error prone, and seems to bite you in the ass with every update. All things that make a bad day for an admin.