For most formats, there's not much public information available on the individuals who make these decisions, but we do know that MTG's Play Design team has some say in what cards are banned
High set up cost makes this one less than desirable for a lot of decks
Gigantoad Rating: 1/10 Weve moved past 4/4 vanilla creatures for 4 mana being good enough to play on their own
Annie Sardelis: I imagine there are some serious Fallout experts who might be able to make sense of some more obscure character's color pie alignments, for instance
In many occasions, youd refuse to make an attack if an opponent just played their big blocker and it isnt worth losing one of your creatures to it, but with this red commander at your disposal, you can remove the blocked creature from play and replay it post-combat so that you dont lose any value and still get through with the rest of your creatures
The Artifact Creature limitation also means plenty of green Creatures that normally can make use of +1/+1 counters (Pelt Collector, Kalonian Kydra etc.) will just be less useful