AITA- [[Imprisoned in the Moon]] in EDH

Hello, I got a blue player question. I play bracket 3 with friends and at LGS tournaments. Is it going too far to [[Imprisoned in the Moon]] someone’s commander in bracket 3?

Imprisoned in the Moon

{2}{Blue}

Enchantment — Aura

Enchant creature, land, or planeswalker

Enchanted permanent is a colorless land with “{Tap}: Add {Colorless}” and loses all other card types and abilities.

I got it recently to deal with pesky creatures that are in the 99 and that can be recurred from the graveyard. I came across a game with an opponent playing a “kill on sight” commander and I enchanted said commander with [[Imprisoned in the Moon]]. The person who owned the commander took it on the chin, but afterwards the pod wasn’t very happy about my play decision.

My play groups typically build crazy value engine decks with little interaction. I build decks that are meant for late game and build over the course of the game. I usually find myself just trying to interaction with my opponents enough so my deck to pull ahead.

With all this in mind, is it mean and inherently bad to cast [[Imprisoned in the Moon]] in attempt to slow others down when said players are wanting to pop off?