My Opinion on Tanks
I don't play Nautilus, Taric, Maokai, Sejuani, and other tanks to deal damage. That's why I choose to play a tank. To eat damage, and unleash CC on the enemy team. I wouldn't mind the pure tanks losing their high base damages, if they could soak more damage and be a threat through a outputting hard cc, not by outputting damage. In compensation for lowering the damage of tanks, % armor pen on an LDR needs to go away.
TLDR: Tanks should be a constant looming threat because of their hard CC, not damage.