They should add a wonder that requires you be in the top 2.5%, costs 175mill, and requires SDI. When you buy this 'super nuke' it would cost about 50mill, no 'super nuke' stockpile, and would do 1k infra damage. The price would be fine for the damage it does and the tier of nations it is marketed to.
Now that would bring some fear back to the upper tier.
Back to topic.
This wonder has its uses in nuclear war but they are limited. By no means does this devalue nukes.