From what I have read this is only a problem when low in iodine.Just take a little supplemental iodine (either kelp or some iodine compound)and don't worry about goitrogens.
Yes, increasing iodine does counter the goitrogenic effects. But not everyone gets sufficient iodine and too much iodine can be very toxic. This is why I prefer to add some seaweed to the diet. It provides iodine, but it would be hard to get enough to become toxic as is the risk with iodine supplements.