My experience is that Magnetizing minions made it way too easy for silence to effectively "kill" several of your mechs without any extra sacrifice made by the enemy. Same thing with Vanish and Psychic Scream.

I wanted to see what other peoples' more analytical viewpoints of why it failed, and what would have been a better way to make magnetic function.

When I first heard about Magnetic, I imagined that it literally fused the minions together a-la build-a-beast. I think that would have been more flavorful and make it a valid mechanic that mechs have over other regular tribe synergies. It made it really frustrating when my mechs would be killed all at once (Especially if I was stockpiling for Kangor's Endless Army)

I'm not upset, but I wish that mechs had a better fighting chance in standard than they ended up having. It's such a fun tribe and I love the art they have. (Also love Paladin) So I'm sad that they never see play because of their "mech" tags.

EDIT: I realize that I should have opened up the question with "Did the keyword fail" rather than "Why did it?" I'm open to your comments as to why it didn't fail after all.