I couldn't agree more, Tom. I mean, Sub is so, so, so strong against melee characters such as Striker, Johnny Cage, Jax, Sonya, Liu Kang, the list goes on.
Of course there's some matches that are pretty tough to win such as the recent Kenshi, Ermac, Kabal, etc. Teleporters/Zonners in general.
But I share the same opinion. I see no reason why give armor to Sub-Zero. In matter of fact, Sub-Zero is one of the few character of this game that I consider to be balanced. I wouldn't change one thing about him and that's coming from someone who actually mains Sub-Zero, unlike most of the players around that cry all day long saying that Sub-Zero desperately need buffs.